JCody, thanks, you're right... don't know why I thought this sound is not of Windows origin... That's some relief.
Again, I totally agree with you that playlist must be repaired, hitting "space" two times before each song is really irritating and I hope Cakewalk will fix it in their next update
You gave me very interesting information to think about this memory overload problem.
But I tend to consider such behaviour a bug. At first, what else on earth playlist could be useful for, but live performances? I think stability and keeping resources usage low must be the main priority in this case, not recording and saving changes. Second, if project gets automatically closed, what's the use of keeping it in the memory anyway?
Automation and synchronization is the main reason why I'm using playlist, otherwise I could as well use Winamp to play audio

. If playlist doesn't work correctly with automation present, it's almost useless to my point of view.
P.S. Just spent some time experimenting with playlist in X3d, made of light-weight test projects containing VST automation. No memory overloads, it seems that projects unload from memory as they should even when I change something on the fly and save changes. This gives me some hope. Can someone else confirm this?