Fix menu position in custom theme

[jrussell]

I've put together a custom theme for JasperReports Server and I'm having a little trouble getting the context menus to position as I'd like. Below is a screenshot from the Ad Hoc Flow, the red circle shows where my cursor is hovering (right over the Change Fields/Select Source context menu hot spot). You can see there's a small but noticeable gap between where my cursor is and where the actual context menu is showing up. The gap is large enough such that I can't move my mouse to the menu before it hides again. I can move the menu item around a bit by changing it's top margin but the size of the gap seems to be different depending on where the menu shows (e.g. if I hover over "View" in the top bar everythig is fine). I'm guessing this is related to the fact that my banner takes up more space than the default theme's banner... maybe.

Anybody know of a good way to consistently fix this menu positioning?