You can hack the CSS files on the desktop, but that will only apply to a per-machine basis. I am not sure the hack can be deployed to FMGo, since the Go CSS files are not accessible as they are on the desktop.
In general, the default styling of popup menus is not really modifiable. This is a known issue that may be addressed in future versions of the product line. For now, if you can't get to it by removing the default style and re-styling to your parameters, then it might not be possible to set.
Have you tried removing styles all-together and working your way up from an unstyled object?
The re-sizing trick is a good thing to use though, sounds like you've already made some user-centric changes to your design.
Mike, thanks for the info. Sometimes the obvious isn't obvious. I'll tweak it a bit, but I took your advice and removed formatting on a drop down list. WOW! So simple and I could even make the font bigger...from 24 to 36. This isn't the finished product, but wanted to show another visual, since picutres are worth a few words.
Thanks, I wasn't quite sure that's what you needed, but glad it helped out a bit.
Once you get that box styled how you want, make sure to use the copy/paste style buttons to set the style of your other popup menus as well.