That is odd.
Are you on a Mac, or a PC?
The reason that I ask is the first thing that pops into my mind, with any sort of display issue is video driver. On a PC, one would want to go to the mfgr's. Web site, and check for an updated driver vs their installed one. On a Mac, the video drivers are incorporated into the OS updates. If you are on a Mac, have you updated the OS?
Though it should NOT make any difference, I would test dragging the WAB past your blank area, where the CTI/Playhead is now, just to see if things change.
I am using a PC. I know this may seem ignorant but what do you mean by WAB?
The problem also seems to disappear and reappear when I edit the preferences.
If I edit anything in the preferences, the problem will reappear and then dissapear if I edit something else in the preferences.
Then I close out premiere and open it again and the problem is back! I just don't get it. This is the first time I've noticed this issue and it is quite annoying to say the least.
what do you mean by WAB?
Sorry about that, WAB = Work Area Bar. That is the little gray area on the Timeline Ruler. It has two "brackets," one on each end, plus a little "box" in the middle. It is used for several functions, including limiting what portion of a Timeline one would Render, or Export (in most formats). I should NOT affect display at all, but let's rule it out of the way early.
On the PC, go to the mfgr's. Web site for your video card. Plug in your card's model and your exact OS. Check to see if you have their latest video driver installed. If not, download and install the latest. Do check the installation instructions, and follow those. They are usually just an un-ZIP, and install over the old one, but it can change.
Try a test with some other media, something from a video camera.