I wonder what the Scorm package you are using was made in. Also what Scorm version. Maybe it uses som IE Active-X stuff. In general I have the impression from various forum posts that most things Moodle work as well or better in FF.
How are you producing your package?
You might want to check the software that your using to create the SCORM package. Some softwares don't work very well with Firefox and they would tell you that.
I had some problem with Lectora when I made a SCORM file before. I really hated it coz I had to tell my client that they have to use Microsoft's IE for it to run properly. Ask Clark what software he used. Maybe that would work for you.
I hope this would help you out. Good luck.
especially the first point.
Thanks for all the advice and apologies for being 'fact deficient' in the original question. The software I am using to create the SCORM is something called TutorAuthor and it does download some Activex files when you first attempt to run the SCORM within IE. Could this be the problem when using FF?
Again thanks for the help - from a Moodle novice.