It seems that I have discovered a bug with PE v12.0 when rendering out to the .wmv format and is best illustrated when exporting at 1920 x 1080. The discovery process began as an observation associated with and more fully detailed in another post
The issue is characterized by the addition of black stripes flanking the video area:
The issue becomes even more evident when placing scaled content on top of the base clip as its intended position is misscaled in the x coordinate relative to the anchor point.
Are there any other PE v12.0 users seeing this problem when exporting to .wmv?
Of course the easy work around is to never export out using the .wmv format and while in most cases allows the job to get done, doesn't communicate to Adobe much interest in seeing the issue resolved for PE12 users. If any other PE v12.0 users have seen this issue when exporting to .wmv, please let us hear from you. Who knows, maybe this could get fixed before v13.0 arrives?
Is this a different issue than the one you brought up in your other thread?
If not, you probably should continue this discussion in that thread so that we have the background and we can have access to what you've already tried.