Ok, so I’m going to blog all this in this thread as it’s as good a place as any.
I’ve reported the bug to Adobe and rebuilt the machine with Win7. So that’s new OS, latest drivers from Nvidia, fresh install of Flexbuilder, latest SDK, latest Away3d, the works.
All good until I fired up the 3D app again. Locked up right away, lots of flickering, then a black screen. Hit the power switch before anything got worse and rebooted. Got some sort of mangled 8 bit graphics at 640x480. Was a bit worried that even the BIOS had yellow stripes on it. However, an uninstall/reinstall of the graphics card has fixed it for now.
Going to proceed a little carefully and try some demos and the like, then start back with my own code.