sorry if this is in the wrong category but i didnt know where else to put it.

Basically, Whats happened is that my internet connection has gone really slow. I know its gone slow because it used to be much faster and around a week ago it just started loading pages real slow. My firefox is tweaked to get the best results but still its taking like 1 minute to open a page.
Personally i dont think its firefox, i think its something to do with my wireless connection. When i sit next to router with the laptop (Netgear DG834G) it works at a decent speed but although my router is only placed one floor below my room, when i try to use it from there it becomes soo sloooww!
I'd like to point out that my router used to be placed on the bottom floor and i used to surf the web with a good speed but then this problem occured so i tried placing on the middle floor but still its the same old s**t!!!
any help or advice on this matter would be appreciated GREATLY!
thanks in advance.