I'm still struggling with this problem. I thought I wouldn't mention it here again and try to solve it some other way, but I can't find some other way except format and reinstall, but heck! this is Linux, I shouldn't have to reinstall, and I've been too busy and need the machine, I can't afford the time and effort right now.
I gave up on the wifi entirely and have been using my DSL connection with an Ethernet cable. Which I hate because the cable, kept strictly for emergencies, now has been winding around a corner in my office to keep the PC tethered to the router. Messy.
So the problem still stands, except that with the Ethernet cable I've discovered that I can restablish my Internet connection instantly every time by simpling disconnecting the cable and hooking it up again to the Ethernet port a couple of seconds later. Something I could not do with my PCI wifi card.
Does that shed any light? Does anyone have any idea what this could be?
Incidentally, I still have the problem I have described in another topic
, although that occurs a lot less frequently now. I hope that someone can help me with that too.