I've tested both of those (thanks for pointing them out) on another site we have (to try and eliminate the chance that it's our configuration) and also on http://demo.moodle.net/ and neither seems to work which would suggest an upstream Moodle bug. I would have tested on https://sandpit.totaralms.com but Direct AICC URL isn't enabled for SCORM activities on there so I can't.

I can't seem to track down a Moodle 2.5-based system to test this on, but it was certainly working pre-upgrade.

Thanks to everyone for their help in testing this and trying to work out what's wrong.

Regards

Dan