comment text input area

ARGHHHHHHHH!!!!!!

What is it that controls the comment text input area? I am trying to port a couple of themes from other sources and when I snatch even the basic comment code from classic for the comments.php template, I am getting an infinitely wide text area. this happens whether I use a percentage, width or number of columns. I am ripping my hair out and its very painful.

please help an old lady see the light!