I've had a ton of problems related to using wifi with my intel 2915 wifi card.
http://forums.fedoraforum.org/forum/showthread.php?p=558619#post558619

Some of the problems are hw/firmware specific, but the 3.0 version of ipw2200
seems to have solved the situation. 

However, I still have problems switching profiles. Troubleshooting is difficult,
and it's hard to figure out which commands/gui tools are taking precedence. 

For example, I can activate a profile for a wifi device in system-config-network. 

However, if Network Manager can't successfully connect to a wifi network, it
will deactivate the wireless device profile. That seems wrong. Aren't the two
things independent?  (after all, I can activate the profile without necessarily
being connected to a network). 

I the user am unclear whether I need to reactivate the network device profile
again or whether the Network manager  will do so on its own  when trying to
connect to the wireless network.