I saw this posted from last year. I just started having the same problem. I updated to 5.5.2 and the program started crashing every time I hit the eye-dropper with Ultra Key.
It was running fine for the last month through some pretty intensive green screen work.
I also installed Silverlight and an mpeg converter but have already trashed both.
Mac Pro 1.1; OS 10.5.8; 13Gigs RAM
Retrieving data ...