Wifi connection issues with 3g

My wireless connection has worked flawlessly forever but the other day it started giving me trouble. Itsays it is connected but won't download data. The only way to get it to work again is to take my email off push and then turn airplane mode on and off. The connection will then work for about 20 minutes maybe and then I have to do it again. My wifes phone works fine so I know it's not a network problem. Anyone else had this same issue. I'm using 3.1.2 software and it is jailbroke using blackrain.




Update. I did the erase all settings and content in the settings tab. Then tried to connect to wifi again, same problem. My wife has a 2g iphone and it works fine. I just took my phone to the apple store and it was able to connect to their wifi fine. I have reset and updated firmware on my wireless router (linksys WRT54GS) and still no luck.