I couldn't sign into AIM either using Conversations or Pidgin on my N900. I found online that you have to unchcheck the box "Use Client Login" in the advanced settings. Worked fine for me after that. EDIT: I accidentally wrote "check" instead of "uncheck" the box. the box was checked by default and I had to uncheck it to get AIM to work last night. The weird thing is that I've used AIM and pidgin on my phone before and it worked fine.