I can't see anything wobbly, but since you haven't attached the actual images nor provided any info about critical things like comp settings, render settings etc., this is a moot point. We could speculate all day and still not figure it out. Start by checking things li9ke comp pixel aspect ratio and the relevant preview functions, then look for unwanted scaling issues and all that...
Just drag you screenshots into the reply field on the forum or use print screen and paste. EZ as pie. Without seeing what you are seeing we can't give you better advice than Mylenium already has. This is not a known bug.
We didn't hear back from you. Did you ever solve this problem? Please tell us how you did that if you don't mind, or do you still need help?