Airport Express "goes Ghost"


I recently put an airport extreme card in my G4 & purchased an airport express to use with it. After about 24-72 hours of the airport express being plugged in, i get dropped from the internet, (indicator on top right of screen loses all bars), and my network shows up intermittently. Sometimes i can join back, but mostly i get the "there was an error joining the network" window. Green light is still solid on the base station. I called tech support & they told me my OSX (10.2.8) wasnt compatible with the current generation of express base stations,(even though it worked), so I upgraded to tiger. I am now running 10.4.2 .
After the OSX upgrade i am still getting the same deal. 48-72 hours, and my network dissapears. Soft & hard reset's dont work, only resetting it back to factory specs & creating my network again allows it to work.
I also access the internet with my Dell laptop through the airport & it poops at the same time as my G4.
So am i looking at a faulty base station maybe? Any help would be much appreciated.