includepollresults.php

// Grab the tablewrapper
list($tbopen,$tbclose) = $html -> table_wrapper();

should be

// Grab the tablewrapper
list($tbopen,$tbclose) = $html -> table_wrapper("full");

otherwise if the width set up in pixels not percents, poll results table would stretch the forum layout rather unexpectedly.

nice catch

There is the same problem with preview post mode if you use pixel value for table width in CP->general options (i think). It stretches the enclosed preview table to the full width and therefore stretches the rest of the layout. I just removed $tbopen from the template and replaced it with the actual html code where the width was set to 100%, since the same table_wrapper was used for several tables on the same page, and I just couldn't be bothered to modify the code.