Been reading this thread, as yes I'm having the same problems >.<
We have the wireless netgear DG834G - and like all it seems to randomly drop its connection every so often (most times when I'm downloading, and away from the computer). I then have to disable the connection and enable it again to pick it back up (or simply just restarting the PC).
However, and this is the weird bit - my partner and I use the same connection (with the same wireless reciever cards) BUT his never drops connection.... and suprise suprise he has Windows Vista... I have XP (home).
We have taken your advice too, and placed the router and its little feet clips so its standing up now - but if that doesn't work I'll be upgrading to Vista to see if there's a difference. :/
Fingers crossed!