Nice menu horizontal not displaying correctly with IE6

Thanks for this module which is great.

I hope this is not a duplicate but my search through the issue queue did not turn up anything that helps me resolve this. I expect it is some sort of CSS issue.

I have a horizontal drop down nice menu in a separate region in a fluid width Zen theme with left and right margins to center the nice menu somewhat. In FF it works just fine, but in IE6 the menu items to the right display in a box that is higher and spans multiple lines rather than moving down to the next line. As the fluid width is adjusted this problem is encountered at particular widths presumably related to the label of the right most menu items. I am attaching two screen captures to show the FF behaviour which is correct and the IE6 behaviour which is not.

I am using Nice menus 6.x-2.x-dev from 2009-05-06. Any suggestions on how to solve this would be appreciated.

Thanks,

Izzy