I should also add, the the whole experience of the 4.5 Beta seems much slower on my PowerBook than 4.4. If I click on a file to select it, it can be a second or more before the choice is made, and as I move the mouse cursor around the contact sheet the appearance of the rotate, preview and Info buttons lag behind the cursor dreadfully. Generating the thumbnails is also much slower, the appearance of dropdowns, everything. Previous PM Betas I've found myself using for real assignments as they've been clearly much better than the outgoing version, but this Beta for me is very sluggish and I have to force myself to use it for testing. I have been tesing plenty with it, but for actually looking through pictures, 4.4.3.3 offers a much better experience.