exits fine for me

Both the 4.2 beta and current 4.2 browser are working fine on my phone.  No lock ups upon exiting.  You might want to try deleting and reinstalling.

I've had it freeze up on exiting a couple of times, As well as some of the games and other APPs. Does yours do it every time?

When you exit Opera, instead of just hitting the Home button, click the menu button in the lower left corner of the screen and exit from there.

See if that lets you exit without locking up the phone.

No issues exiting opera or the beta by hitting home key or exiting through the menu. Also i read about some peoples phone freezing while the phone exits opera due to low battery. Again no issues there.

I've noticed a lag sometimes when I hit the 'exit' button...  It might take a second or two before it actually exits, but it doesn't stay stuck.

When I exit opera I hit the home button and press exit it does stay stuck, but if I hit home again then it will go to the favorites screen.

  Well, I take that back...  Today, my Instinct locked up upon exiting Opera for the first time...  ALL buttons were dead.

  Guess I'll use the menu exit from now on.