Would it be possible to consider enabling the <colgroup> and <col> HTML tags, which according to the design guide I favour (http://www.ncdesign.org/html/060table.htm) work fine for all versions of IE since IE3, and for Netscape since v6.
The <thead>, <tbody> and <tfoot> tags would probably also be helpful.
I think this would allow a great many contorted and cluttered tables to be tidied up considerably.