Nikkol, your're right about what the problem is. It seem that it only gives problems with images (and "code"). Don't know why.
But in my opinion it's quite irritating to have a "unused space" in the right end of the table, and it really screws up my layout (because i have a header that i exactly 805 pixels wide - and the tables are set to a width of 805... which works just fine unless there is a picture messing things up.