Ok guys i seem to be experiencing problems with my wireless setup and i need some advice. I dont know TOO much about it but i know enough on how to hook it up...Here's my setup

Linksys Wireless 102.11B Router
Motorolla 102.11G USB Wireless Adapter.

Ok so the wireless card and the router are about 2 feet from each other. It seems like from time to time it'll connect and then it'll drop the signal and wont pick it back up unless i disconnect the USB thing and reset the router. Now i thought the USB device might be bad so i went and tried another one since i bought 2 of them. Well they both are giving me the same problem. It wil be connected fine...then i'll notice the signal fading then all of a sudden it'll drop and then tell me that it cant pick up an IP address. The wireless card is compatible with my router since it says also can be used on 102.11B. If anybody can shed some light on what can be the problem it'll be greatly appreciated.