Internet Explorer and CSS Menus

I have implemented a CSS menu using version 2.0
Its a horizontal menu with dropdowns on certain items. In Firefox this all works perfectly, but in IE the dropdowns always dissapear before you get chance to move the mouse over the items.
Is this a bug?
Thanks
Ian

After reading all of the posts in this thread (and having spent over $1000.00 for Webassist Software myself), I share the frustrations of its users. It seems that all we (the users) are doing is providing "our" sites to try to show the problem and then being told to try this or that to fix it ourselves.
I have another suggestion - perhaps Webassst could use their very own brand new "Power Store 2" Demo which they are trying to sell to everyone to see the "EXACT" problem everyone is talking about! Now that they themselves are showing this "bug" to everyone worldwide, perhaps they will use some of the money all of us have already given them and pay someone on their staff to actually fix the problem.
Webassist - the ball is in your court - your "action" (not words) will help all of us users understand your interpretation of the phrase "Customer Support"!