Experienced AE user, I've had similar problems to this before but always solved them through fiddling with memory allocation etc, but this one has me stumped.
Got a freshly installed and patched version of AE on a newly formatted workstation. Updated graphics card drivers. Clicking the RAM preview button in the Preview window works fine, renders an infinite number of frames as I've come to expect. However, the shortcut keys '0' and '.' aren't working.
Even with the entire comp in RAM, full green bar, hitting 0 will only play 40-50 frames before playback drops, but clicking in the UI works perfectly, with sound, no issues. This is where the first question comes up: what is the functional difference between the UI and the keyboard shortcut here? I wouldn't have thought there was any but the way I prefer to use just isn't behaving.
I can ctrl-scrub to preview audio, but hitting '.' brings up 'Mixing audio preview' for a few seconds, which then disappears.
I can get audio previews through scrubbing, but this is not ideal for workflow. Also having to find and click things in the UI when I'm used to keyboard shortcuts is getting me frustrated.
If anyone has any ideas for what might be causing this or has encountered and solved this problem themselves, I'd love to hear from you.
This is strange... Possibly a problem with the system language/keyboard setting and the ae language...? Check that both are the same -- ie, both are US English... Though the ram preview issue is strange