Plus you are making assumptions about the resolution the user is view the page at. Your site for instance is incredibly difficult for me (notice I’m saying me) to read because the frame at the top is sucking up a large amount of space.
I do this every day, it is my job to make complicated J2EE applications perform well under heavy loads. Haven’t had an issue yet.
EDIT: part of my job
EDIT2: Again, since you are the one who has to deal with maintaining the site it is obviously up to you.
Some food for thought:
http://www.useit.com/alertbox/9612.html
http://www.webstyleguide.com/page/frames.html
http://www.doghause.com/top15.html
of course you can probably find one hundred pages saying frames are great. 

