Mini DisplayPort to VGA adapter not working under Vista (Boot Camp).

Why are all of you guys knocking apple so hard for what is obviously a windows issue? I came to this thread because I'm having a similar problem on a dell laptop running vista with a displayport to vga adapter. Guess what, 640x480 resolution. I'd like a solution as much as the next person (and will hopefully find one), but why in the world would come from Apple? These work on OSX right? Give 'em a break. (I also own a macbook)

Thanks for the info. Sadly, I'm actually glad that the problem may be more widespread, because then perhaps a solution may come more rapidly. Please keep us informed if you find any insight/solutions anywhere else.

Another disappointed customer. What amazes me, is that this "bug" is the sole reason that I am not buying a new MBA. Moreover, after being a devotee for the past 9 years (purchased 3 macbook pro laptops and 1 Mac Pro workstation), I am going to give away my less than 1 year old Macbook pro and replace it with - this is a good one - Acer $800 laptop.

It's not that I want to, but I just can't continue stepping into meetings not knowing whether my laptop will awake from sleep, nor will it work with a projector. Unfortunately, my job requires me to boot into Windows, so using only OS X is not an option. Too bad for me and Apple.

I have This problem to!
Windows 7 and Vista (32 bits) running the latest Bootcamp 3.0 drivers or the latest 186.81 WHQL Nvidia Drivers. None of them seem to let me choose a higher that 640x480 resolution in any presentation Device available in my university (and that a lot of them ...) Benq, Epson, Samsung, Acer and infocus.

I've already use other VGA adapter and the problem is the same. The only solution is to export My work from iWorks format to Office And run all stuff on a windows machine, thats a joke for my colleges :\

I have same problem. I tried to use different cables and VGA splitters/amplifiers. Also i tried to reinstall drivers and OS Windows 7 and Vista.
Last time i decided to install XP with SP3 integrated. Then Install Boot camp 2.1 drivers from original iMac DVD. Now its working!

It seems the driver 186.91 works. That driver is only for geforce 300M, but works with geforce series 9M. Its an "microsoft update?!"
My source:
www.computerbase.de/downloads/treiber/grafikkarten/nvidia/nvidia geforcenotebook-treiber/

i just got myself a USB Display adapter (basically a USB graphics card). This thing is not much bigger than the DisplayPort Adapter to carry around with and does the job perfectly, at least for presentations. it's probably not the best solution for high res or overlay video, but then you should use DVI anyway.
I got the following model : Delock USB 2.0 > VGA Adapter Nr. 61931
http://www.delock.com/produkte/suche/DelockUSB_20_VGA_Adapter61931.html

Here is some info from NVIDIA that sheds some light but does not solve:

"I think the problem is likely to be caused by either the length of the cable or possibly some device in between that is breaking up the EDID information. [EDID is Extended Display Identification Data]

"Under MacOSX, the operating has preprogrammed resolutions support. However this is not the same under Windows so if the projector does not transmit or if the EDID is not received by the notebook, it will result in your not being able to select the modes your projector supports.

"One quick way you can check after installing these drivers is to right-click over your Desktop and select "NVIDIA Control Panel". This will bring up the NVIDIA Control Panel. From the left column, select "Set up multiple displays" with the projector having been connected already. If in the right panel, it displays correct the name of your projector, then the EDID is likely being transmitted ok."

So my amateur interpretation is that some of the things noted in this thread like longer cables or intervening devices could be blocking the EDID from the external display. I guess Vista defaults to the lowest resolution if it doesn't recognize the external display. OSX, on the other hand, has some support for pre-programmed resolutions other than the lowest. I wonder if this feature of Vista is an "improvement" over XP and whether there is any workaround.

NVIDIA had recommended trying the 186.81 driver on their website, which I have not done yet.

the 186.81 driver is not working, but the 186.91 driver "microsoft update" works fine.
source: have a look to my last post.

Just a general note--this is NOT just a "windows on mac" issue. Far from it. I've got 92 iMacs with this issue, about 12 of them connected to external displays or various sorts. It's not about EDID--it happens whether there is a device connected or not. This issue shows up on the mac OS side--simply loses contact with the DisplayPort adapter. Mac has acknowledged this--but apparently has NO FIX as of Friday, Sept 11, 2009. The firmware update is useless. Incredible. These machines are useless to me, and I expect to be asking that they take them back--how is it that there has been no fix, and they continue to ship with this problem since at least March? Or is it solved on more recently shipped iMacs? I'm going through various motions with tech support on this, but my only option is to pull these machines and return to the Dells they replaced. Nice looking door stops, but that's all I've got from Mac at the moment. I stuck my neck out to purchase Macs for my institution, and all I get is the chance to troubleshoot an issue Apple has been aware of for MONTHS! My disappointment with Apple on this massive. I thought they were a company that cared. My bad.

Sorry, i have tested the new driver with a beamer today. It doesn't work. The driver works fine with monitors but not with a beamer. HDMI-plug is working but not VGA. Sorry

I found and isolate a problem when using vista via bootcamp with a video projector.
When I use OSx or Windows XP I have no problem at all detecting the device and I can change the resolution.
But When I use Vista or windows 7 (32 or 64 bits). The OS do not detect the device and the maximum resolution is 640x480 (cable used is about 5 meters). But if I change the VGA cable to a shorter one, (2 meters) windows 7 / vista detects the projector without any problem.

I think this can Help isolate the problem of the bootcamp video driver for Windows

The driver 186.91 don't work for me

Thanks for the tip. Another USB Display Adapter (conrad electronic) works with the beamer too. That's my solution now untill the Mini DisplayPort to VGA will be working.

I'm glad someone else has the same problem. We just purchased 35 iMacs this summer. We've also had the lose the cloning in the middle of instructor's presentations and the project giving us an "out of range" prompt. However, when our computer people contacted Apple support, they were told it was a Windows issue and when they contacted Microsoft, it was a Mac problem. But this is something I can pass along.