Actually, it's all based on the resolution of the screen and the size of the browser. My avatar is scaled down to 150px wide and shows up completely, as do all others. However, if I scale my browser's width then the scrollbars show up after the table resizing starts to shrink the left column. The lower your resolution (800x600 vs 1024x768) the less space there is for the browser content as well, and thus the avatars will scroll. My resolution is currently set to 1600x1200, but that is exceptionally high and not many people will be able to set it that high.
