Height of 5px cannot be set on ui-progressbar?..

Height of 5px cannot be set on ui-progressbar?..


I'm trying to create a custom progressbar, which among others is of
5px height. It is ok with all other browsers, except IE6 (I know it
dies out, etc, but according to current stats it's still more then
Safari+Chrome+Opera altogether). It looks and feels like something is
keeping it from shrinking to 5px, it does become thinner a bit, but
then it stays constant (approximately at 30px of height)... ?
Any help appreciated.