Not expanding sufficiently.

Hi,
first let me say - great product, especially as a freebee.
I like it so much that I'm currently using it on my site, despite the fact that it isn't working 100%.
bikerman.co.uk

The problem is that my menus are quite large and the menu doesn't always expand suffficiently to show all the entries.
Unfortunately it doesn't seem to fail consistently, so I can't say - go here and click this - to demonstrate. It usually seems to happen when you are in 2nd or 3rd level of the menu and there isn't currently space on the screen. Sometimes it behaves properly and opens a gap, sometimes it doesn't.

I know this sort of inconsistent error can be infuriating to debug, but I'd be grateful for any advice...

hi
I have clicked over a hundred times on the elements from all levesl : no issue.
CED

LOL....yep that's the trouble with these intermittent ones

I can reproduce it* fairly consistently by clicking first on the Entertainment top level entry and then on the 'video' sub-item. This should open to show a sub menu but often the sub-menu either doesn't open, or opens but the menu doesn't drop down to accomodate it (can't tell which).
If I then open up a bit of space (by clicking on the audio sub-entry for example, cliching back on video then usually works properly.

*Firefox 10.0.2 running on Intel/Windows 7.