I haven't seen this behavior on any versions of PT, and I'm now on 10.3.5.
Did you un-install previous PT versions before installing 10.3.4/10.3.5? That is recommended by Avid.
Have you tried to trash PT preferences? Repaired disk permissions with Disk Utility? I always do that after installing/updating, and restart the Mac.
Below is a link to general troubleshooting tips from Avid.
http://duc.avid.com/showthread.php?t=54888