I have actually made some changes to the design away skin - I have a new release coming out - it's a commercial one - and I have been playing with the menu again but what happens is on the second level in FireFox - it doesn't show the background correctly.
I have managed to fix the blue hover state that shows, and tried to improve it as time goes on, but I guess that menu, firefox and dnn have always been a bit of a struggle.
I will be releasing this skin very soon -
Here's what it will look like -
It requires a little more tweaking of the menu - which - after DNN 5 won't work anyway - and I have been unable to get the nav menu to even get close to this - so I had to put it down.
I will endeavour to get this all online this week.
Please not - this is a commercial skin only - I will fix the css for the free one, but this is one that many people have asked me to do - so it's got more options for background images and it has a nice PSD file so you can create your own.