According to my tech-support guy, Kernel.log file shows that "VMware Network Interface" is active whole time (even if I'm not using it, running Win7) and according to him it gets started just before the Wifi drops...
He doesn't say that VMware makes this Wifi drop issue but might be a good direction to look into.
I have VMware installed from almost first day since I got my new iMac, so I can't say did this Wifi drop happened without VMware installed.
Someone was talking about setting up router...
Anyone tried with "Group Key Update Period" ?
Here is an explanation - http://homecommunity.cisco.com/t5/Wireless-Routers/group-key-renewal/m-p/26346
BTW, I'm using WEP/WEP2-Private with automatic selection of encryption (TKIP/AES)...
"Group Key Update Period" is set to 0 which is "disabled" state...
But, it took the purchase and installation of a new Airport Extreme (http://www.apple.com/airportextreme/).
It appears that Lion is simply not compatible with my eight-year-old Airport Express (and, judging from previous posts, numerous other wireless routers). Whatever Apple has built-into (or left out-of) Lion's programming is a major faux pas, indeed, rendering gazillions of wireless routers obsolete.
On the "plus" side, the speed and performance of Airport Extreme is awesome. My network is comprised of my new iMac, my wife's old iMac G4, our two iPhones, an HP 6500A Plus wireless printer and TiVo Premiere. All are now performing fast and flawlessly.
But this Apple WiFi boondoggle should really be a business school "case study".
As I've been reading all over about this issue, few people isolated this issue about "incompatibility" with their router...
Here's another topic on this (or similar) subject:
...and on the last page one guy says he solved WiFi drops.
It was all about the new drivers of Wifi adapter (Atheros) which are 4.0 that came with Lion, and basically he downgraded those drivers to 3.2. And that was it...
Continue reding the whole article here:
BTW, today, my tech support says that I should try with clean install of OS X, and if that doesn't help then we'll try with replacing Wifi adapter in iMac.
I did the driver downgrade (Atheros Wifi adapter 4.0>3.2) as described here - http://rys.pixeltards.com/2011/09/04/osx-lion-wifi.html
...with no problems, simple and straightforward as described.
I can now just wait and see how will this all turn out.
I'll keep you posted as soon as I have either wifi drop again or a week of uninterupted work (hopefully the later).
I did as described on that link, successfully downgraded the driver.
But, now I have new problem - I cannot make my iMac automatically connect to my Wifi network which is set as only preferred...
I tried everything I could possibly google on this subject, and nothing helped.
Interestingly, when I boot into Recovery mode, the autoconnect to my Wifi network works...??? It got automatically connected...
Does it reads configuration from the same place where the "regular" boot does or maybe it uses those "default" 4.0 drivers insted of downgraded ones ?
It seems I've fixed it without having to buy a new router (I would NEVER spend more money on Apple products - such as a router - in order to fix something brand new from Apple that should be working fine).
I installed DD-WRT (a free linux-based alternative firmware) on my TP-Link TL-WR1043ND router and now it seems to be working fine.
Well the 10.7.3 update has had no effect on fixing my connectivity issues. No wake from sleep, frequent random disconnects - still there. I was really hoping this update would do the trick. This is beyond extremely irritating.
My iPad, iPod Touch all connect to my router reliably. It is just this expensive paperweight, 2011 iMac that is the trouble maker. It is to the point where I'm using my old Windows laptop for VOIP and such. I think I'm going to backup my docs and reinstall OS to Snow Leopard. I cannot use this computer like this anymore and I'm done being patient for an Apple fix. (I am not convinced this is a Lion problem, but back dating to Snow Leopard is the only thing left to try).