Randomly dropping WIFI connection

My MacBooks Pro is losing its WIFI connection at random intervals, again and again. Can be an hour, can be 2, or thirty minutes. This is really a major annoyance, as it's causing me service interruptions and data loss.

Here are a few hints:

This is only happening at my home office. I haven't had this problem at other places, although I know from online forums that many people are having this problem, too (even though they're not at my place :) )

This problem hasn't occured before an OS update that I installed through Software Update, but I don't remember which update it was - it's been a while...; my world was soft and smooth before that (MBP wise at least!)

Once the MBP has lost the connection, I have to manually re-connect to my network even though the password is stored in the keychain and the MBP connects automatically under "normal" circumstances (wakeup from sleep, reboot, etc).

My network is protected with a "Personal WPA". I've tried a diferent router that used WEP, but that didn't help.

There are a few other wireless networks in this building.

I've tried switching Channels. No difference.

This has been going on for months without a solution from Apple.

Please someone fix this or at least talk about it. Even only something like "We're aware of the problem" would make feel a bit more confident.

Thanks,A.