Choppy playback after upgrading hardware

I’ve recently upgraded from a phenom 965 and 7gb 1333 gb ram, to an i5-2500k with 16gb 1600mhz. Otherwise everything is the same, i just reinstalled windows and premiere pro after the upgrade. After the upgrade this error, or annoyance, occured. Here’s all the specifics:

 

-Premiere pro CS5.5.2 v/latest updates

-Windows 7 pro (fresh install v/important updates)

-h.264 in mp4-container

-no error messages

-very choppy playback after “jogging”. When theres a lot of movement, the picture becomes very “stuttery” and “pixelated” in that area.

-no extra codecs or similar is installed.

– hardware:

   -nvidia gtx 560 v/latest drivers

  -i5 2500k @ 4,6Ghz

  -16Gb 1600mhz xmp ram

  -7200rpm 500gb source hdd

  -5200rpm 120gb scratch disk

  -Agility 120gb ssd OS and programs

 

I have tried using 1/4 playback, using ssd as scratch disk, installing and uninstalling extra codecs but none of it made any difference. The cpu or ram never exceeds 50% capacity when the problems occur. 

via Adobe Community : Popular Discussions – Adobe Premiere Forums http://forums.adobe.com/thread/1091246