My web page reads fine in Chrome, but on one of the buttons in IE half of text disappears and in Firefox it shows out of the box

The page is http://www.c5d.co.uk/descriptioned51891.php

Is the real answer to increase the button size, or reduce the text size in the button ?

I hope not because I want to keep the button & text all the same on all my pages

Thanks for any help

Antony