Alright guys, thanks for your help..

But i just realized i have a HUB not a router.

I dont know if this could be the problem?

 

hub is a dumb device.. get a router...
you can be getting signal collision.

 

um, well if you have the internet connection going into the hub then being split off to the network either your using one of your pc's as a router or the modem has a built in router because you can't just go modem > hub > pc's.

 

Once again, I'll say: Get a router.

D-Link Wireless G from Best Buy, $39.99

Netgear Wireless G from Best Buy, $49.99

Netgear Wireless G from Circuit City, $39.99 (After $20.00 MIR)

Linksys Wireless G from Best Buy, $69.99

Linksys Wireless G from Circuit City, $49,99 (after $20.00 MIR) < I really recommend this.

I listed Wireless G stuff, cause its not that much more to get the router with wireless capabilities, so might as well get it. Circuit City right now is having sales routers, with Mail In Rebates of course, but its still good stuff.
For about $20.00 more, you can get the routers with 108Mbps Wireless speed. Nice to have, if you like to do alot of file sharing between computers.