Absolutely funny! :)

Sorry but I didn't consider this possibility, so there is no easy way to change the shadow file name, other by editing the hmenu.js file itself (which might not be easy as, depending on your license, it may be stripped of white-space).

The string "shadow.png" should only appear in one place--try changing it to "shadow-1.png".  You should also change this in "hmenu.css", in order to have the shadow image preloaded in Internet Explorer.

If you still need assistance, I will be able to help only on Monday as I am on vacation.  Please let me know how it goes.