Frequent Freezes in Unity Pro with 0.4.3

Have any other developers been getting frequent freezes while developing their game?

My freezes USUALLY happen when trying to stop the Play Mode. Unity just stops responding. Eventually... maybe after 30-60 seconds, Unity starts responding again. This is with Unity 4.5.5f1.

Please respond if you have had similar problems, as well as your Unity version. I'm trying to figure out of this is just isolated to my machine, or if maybe its a problem with the latest SDK.

EDIT:
Here are a few screenshots I took in Process Explorer. I don't know if this will help you guys, but its worth a shot. When Unity freezes, one thread seems to take up 25% of the CPU power.

#1: Screenshot of Unity process in Process Explorer
ovrfreeze1.png

#2: Supposedly, the stack for the thread stuck at 25%. What sticks out to me is the mono breakpoint callback. But I didn't have any breakpoints set... and the debugger wasn't even attached to Unity at the time of freezing... so..?
ovrfreeze2.png

#3: Shows GPU usage. Two points of interest. While playing my demo, I got a random freeze for about 5 seconds. That's the dip in the middle. Then, the tail end, you can see the GPU is completely unused during a freeze.
ovrfreeze3.png

Hope this helps.