MBP 15" connected to Dell U2711 monitor - PCIe malfunction?

Hi all,

I bought a new MacBookPro 15" this summer. I also purchased a Dell U2711 monitor and a minidisplayport-to-displayport cable to connect the two. The U2711 is Dell's top monitor with a 2560x1440 resolution.

Here's the deal:
* Connecting the U2711 to my roommate's 2010 MBP 13", everything works flawlessly at maximum resolution. This proves that the monitor and the cable have no problems.
* Connecting the U2711 to my 2010 MBP 15" (everything updated to last version), is a different story. It drives the monitor fine at 1080p (1920x1080), 720p, and a few lower settings. However, when choosing 2560x1440 (or a few less common lower resolutions), there is a very annoying flickering on the screen. After closing the lid of the MBP (which shuts off the screen after 15 seconds or so) and opening again, the flickering is less strong, but still way too annoying to tolerate. (According the a mac store person here in town, closing switches the graphics, which seems to help slightly but not enough.)

I took my MBP to the store, where it drives Apple's large displays without any problem. So my laptop and its displayport aren't broken, either.

What's going on?

SPECS OF THE MPB 13
Nvidia GeForce 320M, PCI-bus, 256MB, ROM revision 3533, ...etc.
SPECS OF THE MBP 15
Nvidia GeForce 330M, PCIe-bus, 256MB, ROM revision 3560, ... etc.

On both machines, the monitor is listed identically (DELL U2711, 2560x1440@60Hz, 32bit color, connection type Displayport, etc.).

The relevant difference is that the MBP13 uses PCI, and the MBP15 uses PCIe (or PCI express). I've come across a few hints on the internet that Apple's implementation of PCIe is buggy or problematic.


E.g., this company ( http://support.villagetronic.com//faq.php?cid=1&answer=3#f3 ) makes external graphics cards, and their faq on mac's says:
[ begin quote]
ViDock 3, ViDock 4, and ViDock 4 Plus adapt PCIe cards to an ExpressCard slot. They work with any compliant ExpressCard slot, including the slot in the MacBook Pro. PCIe cards that do not require a large PCIe memory window, such as professional video editing cards and storage controllers, will work with MacBook Pro and ViDock.

However, only MacBook Pro generations 1, 2, and 4 support graphics cards on the PCIe bus provided in its ExpressCard slot. Other generations of MacBook Pro impose limitations on the memory resources allowed to be assigned to PCIe devices in the ExpressCard slot. PCIe graphics cards used in ViDock require more memory resources than are allowed.

[...]

ViDocks support any MacBook Pro. The compatibility problem lies on the Apple side. If you insert a VIdeo Editing card, Fire WIre Card or Hard Disk RAID controller card, they will all work in every MacBook Pro. But once you insert a graphics card some MacBook Pro models refuse to grant as much memory to the graphics card as they request. (The reason for mentioned cards all work is because they request so little memory.)

So, if you want to use PCIe cards that do not require a large memory window (PCIe graphics cards require a 256MB window) then ViDock 4 will not work for you. Examples of cards that do work are professional video and audio editing cards (BMD, AJA) and storage interface cards (SATA, 1394).
[end quote]



I'm guessing that maybe this is somehow connected to the problems I'm having?



If anyone has further ideas about this, or has succeeded in running the U2711 at max resolution from a MBP 15", I'd love to hear from you!

I'd also appreciate some response from Apple if anyone there happens across this post: I know your and Dell's small print says you don't guarantee anything when combining hardware like this, but really, it's not a far-fetched combination.


Thanks!

Kevin


PS I'd rather not downgrade to a MBP13" as I put the larger screen and extra power to good use. I see no use in upgrading to a more powerful MBP.
Also, I like the Dell monitor more than the corresponding Apple screen (cheaper, less glossy, and it has deep color) - if I sold it on the used market and bought a new Apple monitor, that'd set me back $500 or so.

More specs:
Hardware Overview:

Model Name: MacBook Pro
Model Identifier: MacBookPro6,2
Processor Name: Intel Core i5
Processor Speed: 2.4 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache (per core): 256 KB
L3 Cache: 3 MB
Memory: 4 GB
Processor Interconnect Speed: 4.8 GT/s
Boot ROM Version: MBP61.0057.B0C