Sorry, I meant to say height, not width :) and no, it is not fixed yet :(
17px is the max font-size that works in seamonkey (for that box)... The only way I can get the problem in Firefox is to turn up the font-size to 20px
Setting the font-size to a percent does not appear to do anything at all in seamonkey. I even set it to 10% and there was no difference. With the html <font> tag you can make it something like <font size="+2"> to make it 2 pts larger than the default, but it doesn't work with percents either...
If you just set the height of the entire thing (hfi, hfih) to auto and then set hfxh to 100% height, I think it would work better