This is a documented RoboHelp 8 bug tied to your toolbars.
Forum search should reveal the details...
Feel free to report it to Adobe again if you like.
Helpful and Handy Links
OK, resetting the toolbar fixed my missing styles. I had searched in the forums but didn't call it what others had called it so I didn't see their posting.
The one thing I would add is that I had to select each toolbar and click the reset button. I wrongly assumed the reset button would reset each toolbar and it didn't. Not sure which one was the culpret.
That sure is a mean little bug. I wasted 5 hours on trying to fix it and our IT wasted 3 hours of their time. Bummer.
Thanks for pointing me in the right direction.