Fedora Networking :: WiFi Not Reliable And Can't Change Networks?

Fedora 10 (dual boot w/ XP) on Dell Optiplex with a Dell wirelessntennaI am on a university campus with campus-wide wifi network (so no router). I have a wireless HP printer that I want to be able to print to using an ad-hoc connection. The wireless antenna, networking, and wireless printing are all working in Windows XP (so hardware is OK). However, on the linux side, the wifi is really really finicky.

When I first boot up to fedora, it usually connects no problem to the campus-wide wifi network. If I try to switch to the ad-hoc printer network (which it sees), will not connect and, furthermore, it will no longer connect to the campus-wide network (and sometimes it doesn't "see" this network at all). It seems that restarting the Network Manager service sometimes helps to reconnect to the campus-wide network, but not always and I can't connect to the ad-hoc regardlessNOTE: I'm just barely a linux user, and I didn't set up my system - don't assume that I did anything that would be common sense and, if you can, walk me through your suggestions.