Same for me, updated to 12.6, and it seems fine, issue seemed
resolved, however, shortly after the update, the problem returned. If
boot up my system and the HD TVs are connected (via HDMI), all is fine, but if
I change either of the HD TVs to some other mode, say normal TV, Xbox360, DLNA,
etc., and then return to computer monitor mode at some point, I sometimes lose
the audio. If I turn off one of the two HD TVs and turn it back on, I
almost always lose audio but not video. So as far as I am concerned, the
issue still exists. I don't recall 12.2 or 12.3 ever doing this.
I have a Visio E320VL (VIZ0067) and a Sharp Aquos (SHP105B)
connected to two ATI HD 5450s, one per HDTV, but the issue also happens with
the onboard 4290 as well, for the system in question. The only solution I
have found is to go into the Catalyst Manager, and force the given TV to be
reinitialized via the HDTV EDID override option, this seems to cause Windows 7
64 bit (well, the Catalyst driver) to rediscover the HDTV completely, and thus
restores the audio connection, what is odd is the video connection never fails
to respond, but ATI must understand the specifics of this better than I.
I only sometimes get the dialog popup that says I that I am using a DVI-to-HDMI
connection, which is bull, everything is straight HDMI from video adapter to
each HDTV. But this maybe a clue as to what is going on?