OS X Lion here - all updates, and I just ran Disk Utility and repaired permissions.
aeselflink (I assume this is a render instance for AE) asks for my password many times when I render. I think it's the same number of times as there are instances of the utility that launch.
How can I prevent this? I have a 24-core machine, and typing this 24 times is unnerving.
Check your user permissions and/ or the permissions of the processes as well as potential blockages at the system level. If your user privileges are sufficient already, that may entail some ugly hacking in the console to fix it. In any case, run a tool like OnyX. Even if they may not be able to fix anything, they'd at least report problems. For everyting else, File --> Info is your friend.