Wireless seems to discconect every 5 min , then reconnect.O.o

So i am haveing the weirdest problem and i really can not figure it out..

Basics:
OS:windows xp sp2 on main machine and laptop
Internet: verizon dsl, westell model 6100
wireless card on main computer: zonet ZEW1300PF
wireless card on laptop: 802.11b Wireless PC Card adapter

Ok first of let me start of by saying . iv been having some health issues so i can not afford a wireless router ( which i would love ) but im in debt over my head.

so instead what i have done is connect the modem i have received from Verizon and hooked it up to my "main" computer. this computer also has a wireless card. after that i check if interent is working and it is. after that i bridge the local network connection ( main to modem) and the wireless. after that i get on the laptop and connect to that connection . and wala i have internet on the laptop.. everything seems fine until about 5-9 minutes pass. my connection stops receiving internet(on the laptop). the connection does not get fully dropped. i can still access shareddocuments from one comp to another. the only thing that happens is ANY internet connection that i might have will completly stop.(just on the laptop) then after about 8 minutes(yes i timed both of them).. the internet connection ( on the laptop ) will just come back.
remember the connection on the laptop is always active.. it seems that for some reason for about 8 mintues my main computer does not want to share internet :/

If anyone has anny suggestions it will be much appreciated. This problem is driveing me insane.

P.S. i have also tried a friends laptop and the results where the same.

Update:
i was on irc in the same server same channel seeing how long it will stay online..
when i noticed something weird.. when it loses its connection (internet) its like the send out packets get blocked first.. then the received ones.