Sounds like an issue with your controller. I rarely stray from first party offerings for console controllers. The only exceptions I regularly made were the Logitech wireless controllers for the PS2 and original Xbox. Those worked splendidly.
I'd say either go back to a wired GC controller or see if you can wrangle up a legit Wavebird. Gamestop brand products sucks balls. (Once upon a time I sold a shitload of them, and many of them came back in as defective before too long. I tried warning most as they bought them, but they wouldn't listen to reason.)
The dedication you show to any particular console or company is inversely proportional to the number of times you have gotten laid. If you get laid enough, even if you prefer a certain brand, you just don't give enough of a shit to argue about it on the internet.
