look at the page source and see if any spf stuff is loaded…
but I couuld never get FCG to work on any of my wp installs (even without spf) since wp went to jquery. yes, some have (like you)… sometimes all it takes is a different plugin loading sequence or shift in memory from a plugin… one of those quirks of wp…
I finally got round to sorting this out this morning, I'd been putting it off 
Decided to ditch FCG because it has given me numerous problems since I started using it, this was just the latest in a long line!
Thanks for your code Steve, but I checked up on the progress of the Dynamic Content Gallery and it's come on in leaps and bounds since I last took a look! It's a pretty awesome pluging now that gives you the option of using mootools or jscript. I've opted for jscript and evrything is playing nicely for now.
Guess FCG was one of those plugins that was great when it was released, but due to a lack of updates and support has just died off. DCG has picked up the reins and taken it way beyond what FCG ever did! I'm happy again.