Hello
Thankyou for this very nice mod.
I think I have found a way to make the lag in the tab edges go away, I think some people are also having problems with it, I did the following and it works for me.
Please realise I do not have any knowledge of Java and I could well be missing something that is fundamentally wrong.
When it comes to code of any description I am like a parrot, I can copy and make some very basic changes, but have no underlying understanding of what it means.
This is for Tabs.js in the skin1/customer directory.
My fix did not fix 
I got my mods mixed up, and my positive vibes made me think that I had fixed something I had not, maybe next time.
I hope this can help some people, its a very useful mod.