Unless its been drastically improved in the past few months, linux aim really sucks bad. Many many features don't work, away messages are limited to something like 20 characters, really poor looking interface, etc etc.
I'd recommend gaim, you can find it at
http://gaim.sf.net I'd rather use that then AIM anyday of the week, plus it also allows mulitple logins with many different account types. I use AIM, MSN, and IRC and it does all of them at the same time with one app, really nice program.
Of course if you really want it for some reason, you should be able to grab the libraries from the rpm update program in Mandrake.
