I have installed the plugin and made very small css tweaks to it.
It works fine except for in Firefox on both MAC and PC the height is calculated wrong for some of the submenus. There doesn't seem to be any rhyme or reason for it.
One of sub menus (custom web content) has only one link inside the sub-container div and the bottom border (also part of left & right) is missing from the sub-container div.
However a sub menu with eight items calculates the height correctly for the sub-container div in both Firefox and Chrome on MAC & PC.
Also it seems to calculate the height differently in firefox than it does in chrome. It seems to calculate incorrectly on both PC and MAC in the same way. Seems to be a browser issue.
Thanks and any help would be greatly appreciated.