Hi Andi,
Thanks for your reply. I'm definitely using the correct key switches (i.e. not special edition) and I have Human Playback turned off. To be clear, this is a Finale project that I have been working on for months (and the same basic template that I've used for years) with no issues regarding playback.
The problem started as soon as I opened the project, having moved to iLok and installed VE7 and VIpro (upgrading from version 6.5 I think), and it converted to the new format. I haven't changed anything from the prior setup, so it would be odd it if wasn't connected to the new system or the conversion process.
Thanks,
adan