(Migrated from SuperUser.com due to complete lack of answers!)
I installed a Linksys WRE54G range expander. It's working fine with my Windows 7 laptop, but not so much with my Palm Pre and my Ubuntu netbook. Both of the 2 problematic devices act the same... they see the wireless network, say they're "connecting" for a long time, then finally fail saying they can't get an IP address.
Unfortunately, I think this leaves me in "finger pointing hell" where I won't be able to get support from any vendor, because they will each point to the other as the culprit.