Check the pixel aspect ratio in the Interprete Footage jfor that clip.
Right click on the clip in the Project Panel.
Handbrake converted it probably from rectangular pixels to square pixels.
It says "Square Pixels (1.0)" What do I do about it?
Run the original avi through Mediainfo
That will tell you the Pixel Aspect Ratio.
Set that to the clip in Premiere.
If its the same something went wrong during converting.
It is 1.222 (11:9) but Premiere doesn't have an option of that.