I never had a anoyance in PPRO2 that I have right now. Maybe you encountered the same issue and have a solution for it. I recently completely upgraded my PC. Got the new MOBO, CPU, memory, PSU, Video.

My PC has this:

ASUS P5B-DELUXE Wifi
Intel Core 2 Duo 6400
2 GB of ram
3 HD all SATA
600 WATT PSU.
PCI 16 Video card.

This is problem that I have right now.

When I place the clips in timeline they are indicated un-rendered by the red line at the top of the timeline. Once I start rendering the clips, PPRO2 start normaly, I see the frames count changing, but then its stop rendering for couple of seconds, changes the red line for the completed frames from red to green and then continue rendering the next batch of frames. The process repeats till all the frames have been rendered. Once all the clips are rendered and I press the play button to view rendered clip; PPRO2 start playing the video normaly and then the video portion stops for a second or so, the audio keeps playing, then the timeline marker jumps to the frame where it should have been if it did not stop and the video keeps playing further. The process repeats till the video clip end. The video stops approximatly at the same spot where it stoped while rendering. Not sure why. I have pretty big hard drive, 300GB, both the project and the scratch disk is on the same hard drive, I never changes those settings before and that was never a problem.

I guess the good thing about it is this; if I render the video in the timeline and export it to video the vider will play smoothly without jumping.

Thanks for your help.