ok, forget the audio issue. Something, somewhere has messed up my sound card - the center/sub channel is playing out of the rear left/right channel. I swapped some cables around until I can work out what the hell happened
The demo loads fine. I wasn't aware that valve handled the protection system for third party games - but then valve don't provide any support for third party stuff so it probably wouldn't be much use reporting this to them
here's the error from the vista event log:
Faulting application sammax101.exe, version 0.0.0.0, time stamp 0x4655cfe5, faulting module Steam.dll_unloaded, version 0.0.0.0, time stamp 0x465c94a1, exception code 0xc0000005, fault offset 0x200cdde8, process id 0x1bc4, application start time 0x01c7b081449b3a90.
When it fails in steam.dll it's always the same fault offset - but I'm also seeing a few different faults in ntdll.dll version 6.0.6000.16386:
fault offset 0x00022b4b
fault offset 0x00022950
fault offset 0x0002294f
All 6 episodes seem to randomly fail with one of those 4 errors logged. Sometimes an episode will load first try, others I have to load it 5 or 6 times before it will start.