papaterry33 wrote on 6/12/2009, 1:30 PM
Saw your dated question and replied to get an answer to my same problem, but now I found and copied this from another post:

Subject: RE: V9 Auto Preview Not Working
Reply by: Steve Rhoden
Date: 5/13/2009 4:49:40 AM

Disable the show video monitor button in the trimmer tab,
and you should have your auto preview functioning properly.

Maybe someone else will benefit from posting this here.

daryl wrote on 6/12/2009, 1:56 PM
Kewl, thanks tidum!
watti wrote on 6/16/2009, 11:34 PM
Thank you, this solved the avchd preview problem in V8 too.
R0cky wrote on 6/17/2009, 7:30 AM
Thanks too. This was non-obvious and appeared to be a bug. Of course, I haven't read the v9 manual yet either.
Kevin Mc wrote on 6/19/2009, 11:09 AM
This also worked on 8.0c ~ THANKS!!!
MyST wrote on 8/16/2009, 5:59 AM
Thanks much for the help!

This fixed it for me as well in 8.0c.
DWhitevidman wrote on 8/25/2009, 10:26 AM
I've had this same problem occur and fixed it with this post, thanks. How does this get turned on in the first place? I never use the trimmer.