After the OS update to 10.6.5 (and still true in 10.6.6) I found a really annoying thing happening in DP: if I had a selection - of any sort - the next selection I made behaved as if the shift key were being held down. In other words it would add to the existing selection instead of deselecting it before making the new selection. Similarly, if I dragged over part of an existing selection, it would deselect that part, leaving the rest selected. And so on. As you can imagine, this nearly led to some fairly horrific blunders when editing.
So... I'd just about got into the habit of always doing a command-D to deselect all before making a selection, when I remembered a related problem I'd had in Photoshop CS4, to which a solution was posted on a Photoshop users' forum. I thought I'd give this solution a try and bingo! It works! If you want to read about the background, the forum is here:
http://forums.adobe.com/thread/752602
It's all to do with an API that changed in 10.6.5.
But if you've been hit by this and would rather just skip to the solution, you can download a little hack here:
http://www.bache.name/download/osx/10_6 ... 20hack.dmg
Here is what the author of the hack, Jesper Storm Bache, says:
It works for me, and I hope this helps someone. Meanwhile, I hope MOTU are working on a fix...This application runs and then exits (after trying to remedy the problem).
By the way the application simply simulates a key up event for the following keys: option, shift, command, and control.