Sounds like the card and/or the PowerBook's CardBus slot may not be working correctly.
Do other CardBus cards work with your PowerBook? If so, I would suspect the nQuicky to be defective, in which case, you can probably exchange it for a new one. If not, then perhaps the CardBus slot on your PowerBook is defective -- and that could be an expensive repair.
You may also want to try and zap the PRAM, reset the NVRAM, and/or reset the PMU (instructions can be found on Apple's site) to see if it's possible that a power issue or something easy-to-fix is happening.