Hi I have the same problem with Illustrator CS5 and InDesign CS5 really really slow opening, saving etc. It seems to have started happening in the last few weeks, so it could have been an update of the Mac OS or and Adobe update that has screwed something up.
If anyone knows a fix, I would like to know as well, before it drives me completely mad.
I have found the solution for me.
I had RightZoom 1.7 from BlazingTools installed. This screwed things up.
I uninstalled it and now everything is fine and up to speed again.
Maybe you can check what applications/tools are started on logon and disable them all.
Thank You! Thank You! Thank You! Thank You!
Removing RIghtZoom worked for me!
I only had it installed because I don't like the way windows in OS X don't fully maximize like windows. I much prefer Illustrator to work than have full screen... plus photoshop tool selection is much faster as well.
Same yields for CS6, quit RightZoom when working with Illustrator.
I would have spent many frustrating hours without your help.
I was even about to take the last resort of trying to talk with someone at Adobe!!!
Thanks for taking the time to write an answer!
RightZoom is still an issue in Illustrator CC! Just installed CC and totally forgot to disable RightZoom for Illustrator CC.