dropdowns disappear under iframe in IE6

I need to absolutely position a transparent iframe on top of the form with dropdowns. But when I do so all dropdowns under iframe disappear.

I am testing in IE6 on XP SP2.

Couldn't find any solution in Google. Anybody managed to fix this?

Thank you!

Dasha

This is a limitation of IE6.

The common solution is to hide any iframes when the drop down gets focus, and restore them afterwards