I am a long time Adobe user. For a long llong time I used it solely on mac but recently have been slowly making the move to Windows for everything (previously just for fun).
Anyway I am having some issues getting quicktime to work well on Windows, even on the very same computer that the same project works fine in OS X. I know quicktime is "native" to apple and osx, but in talking to other windows users my experience isn't normal.
First, I am on Premiere Pro CS6 up to date, Windows 8 Pro (and os x 10.8.4), up to date, on a 2008 Mac Pro 8x 2.8ghx 16GB ram, with a gtx 680 (4gb). GPU drivers are also up to date. I use eSet Smart Security for my antivirus. I have made sure that my project/media drive as well as the ssd I use for the media cache are ignored by the eset realtime scanning. Quicktime (pro) and the ProRes codecs are installed. Not a superstar rig but still a capable machine.
The project in question is a short compilation of stock footage. There is a total of 25 clips, the longest of which is 4 minutes, the shortest a few seconds. All are quicktimes, most are prores, some are photo-jpeg and there are a few other codes in there as well. All 720p or 1080p. They are edited down to about 1 minute in the timeline, using a 720p23.976 preset.
On my mac, everything is as expected. I can smoothly play back my timeline, and quickly open clips in the viewer panel. This is instant. Occasionally on the first open of a clip I will get a brief "media pending" screen but never more than a few seconds and only when the clip is first accessed.
In windows, however, there is a very long delay when choosing many but not all clips -- both to open in the viewer OR even just to select or scrub in the timeline. If I have my playhead parked on 1 clip, then move it to another, there will be a delay of anywhere from 5-10 seconds before I get an image. I can see my media cache showing some activity, and sometimes I get the 'media pending' screen during this. Audio uslly works during this time, but no image. If I leave the clip and come right back to it, it will be instant, but if I go to a few clips, when I come back there will be another delay.
It seems like something is going on with my media cache, but only in Windows. I have formatted and reset it to no avail. It seems odd that on mac it would "remember" that it has loaded clips from the cache but on windows it has trouble with the same clips and has to re-cache frequently.
I can try to get a screen grab of the behavior if it will help. I can say that I don't think it is isolated to ProRes because I have had this problem in the past with a project that only used animation clips. I haven't had time to try with a whole project, but I don't seem to have the same problem with avi's, but I need to stay cross platform for now and most people I work with use ProRes.