I'm no stranger to wireless/Vista problems now.
I am on my 4th wireless adapter/NIC, and it is the one taken out of my old computer. It is a Sitecom Wireless PCI Adapter, 54G 115-L. I have the latest Vista drivers for it manually installed from their website. Similar problems to the 2 netgear devices and 1 dlink, but alot better (the drops out now are rarer but still frustrating and can vary from days to a few hours perhaps).
So effectively I am on the same equipment that the old PC was, and that didn't experience one drop out in two years to a BTVOYAGER2091. Maybe the crucial difference was it ran XP, not Vista.
Anyway since Vista is such a pain like this I assume it might be one of the options. I have looked through the more advanced options of "manage wireless connection" and the various properties but I don't know what to touch.
Ringing BT tomorrow anyway see if they have any clues. Basically if I can't fix this, I will have to go wired, but even then I have heard of similar problems under Vista... ?!
The worst part is the diagnosis of this problem. It's like a car running at 125mph flawlessly, then every now and then stopping dead.. say once every few days, once a day, twice.. totally random and unrelated to what it's doing.
Thanks.
Edit - I would just like to add I don't believe throwing more money at this is the solution.
I've already spent £35 on A Dlink USB, £30 on a PCI NIC from Netgear and £25 on their USB equivilent.