This probably isn’t the reason, but I’ll post this anyway.
A recent project in Premiere 6.5 started working very slowly the other day. Every mouse click event took several seconds. I tried rebooting, etc. Then I remembered that I have a small floor fan that I keep blowing on my hard drives when I work – otherwise they get so hot that I can’t touch them without getting burned. I had turned the fan off and forgotten to turn it back on. Once my hard drives cooled down, everything starting working peachy again.
J. D.