No, you are not the only one having this problem. I have been posting about this problem for over 8 months, and I have seen numerous other posts about this issue. The WD box does not remember the video settings.
In my case, I go into the wd setup and set the video output to 1080i, and the color space to RGB Low. When I power the box off and on again, about 50% of the time it comes up set at 720p (which my TV does not support), and RGB High. Also, with the last release (1.04.31) it sometimes sets the color space to YCrCb.
When someone manually sets the video resolution/frequency and color space, the WD box should remember those settings the next time that the box is powered on. That is how every other device works.
The only thing that I can suggest is to leave the box on all the time. Even then, my Live Plus still occasionally changes the color space value all by itself, while it is just sitting there at the home screen. This is a real problem because when this happens, the other members of my family (wife & daughters) have no idea what happened and they have to call me to fix it.
The other thing I can suggest is to send your problem to WD so that the engineers will know how widespread this problem is and maybe we can get them to put it on their list of things to fix.
Here are a couple of recent threads regarding this issue:
