Using an M-Audio 24/96 card in W7 64. Set the card to 128, launch Cubase, and the card changes to 1024. Close Cubase, change the card to 128, launch Cubase, and the card changes to 1024.
Can someone explain to me why this is happening?
Ok, got it. This behavior is seen with an .mov file open in VLC player. Wierd, but closing the player solves this.
Are you sure Cubase has “let go” of the card? check Task Manager/processes to make sure Cubase has shut down completely?
Edit, ah, VLC was holding it 
Yeah - that’s the wierd thing…if VLC is holding it, why am I able to change the buffer with VLC open? It’s only when both are open that Cubase changes the buffer. Wierd.
Hmm… Have you got “release driver in background” checked?
AHA!