First, there was the wireless card which isn't yet fully supported under Linux (supposedly, some people have got it working without WEP, but I haven't even got that far).
Then, there's the scanner which doesn't. Apparently scanners used to be supported by a kernel module up to kernel version 2.6.2. I have 2.6.3, and the new method doesn't work for me. The scanner certainly used to work with my old Linux system, and works fine with a Mac, just not with the current system.
Of course, I Googled to see if anyone else had the same problem, found some who did, found advice given to them, and followed it. Alas, what worked for them hasn't yet worked for me.
Finally, I decided to join the mailing list for development of the scanner software (sane). I signed up from the web page, got confirmation mail and replied to it ... and nothing happened. No mail from the list, even though there's been enough time and it's supposed to be automated sign-up anyway.
(My one success story recently (tonight, in fact) was getting support for AAC encoded files (originally ripped in iTunes on rwrylsin's Mac) working in xmms. Yay me.)