OK, thanks. I did verify that if I use one of the default Joomla templates it displays correctly. POsted something in the JoomlaArt forums to see what they say and in the mean time will start digging into the CSS.

Any pointers on which PHP file(s) control the display of the "Pay Now" screen so I can debug how this is displying on my site / template?

Thanks. It seems that the pointer to the different bootstrap.css (in /components rather than in /administrator/components) that I had going in my other thread seems to have fixed it a little bit. Here is what it looks like now:

you're closer. I'm sure that if you add the apropiate "float:left;" CSS styles to the tabs you should have a better display..

yep - for whatever reason changed float:left to float:right and now it works great!