Running CS4 in Vista 32-bit.......
In Preferences/Previews section, the OpenGL Info button says there's no OpenGL card detected. But when I run sniffer_gpu.exe from the command line, it returns OpenGL 2.0 and NPOT support = true. It also detects both displays with 512 mb available for each. Also, AE_OpenGL.AEX exists in the Plug-ins/Extension folder (506 k). And Photoshop CS4 has OpenGL enabled.
Video card is nVidia GeForce 8600 GT, and I just updated the driver yesterday. OpenGL wasn't detected before yesterday, either. The driver is only a couple of weeks old and the manufacturer's site explicitly says that one of the updates was improved OpenGL. The nVidia control panel has an OpenGL adjustment available, though I left it at the automatic settings. In another thread, I saw Mylenium recommending downgrading the driver to an older version, but other odd things were happening, so I really did need the update.
So if I can put this in technical terms..........what the heck??
Oh, uh.....(cough)...I fixed it. Installed the 9.0.2 update, and AE now detects the OpenGL card. Sorry if I wasted anyone's time; I should have done that, first.