Got a email from a Cary dealer in Phoenix. He spent some time on the phone with Cary about some of the Cinema 12 issues.
Here's what he said,
"The official HDMI standard for an effective 'handshake' process is no more thn 14' from source, with processing thru interface components, connections, equipment to the projector (guaranteed performance according to HDMI standards).
there is a 'black box' that is highly recommended for runs over 14' to achieve consistant 'handshake' processing (to eliminate audio dropouts). http://www.lumagen.com/testindex.php?module=hdmiext
the audio dropout problems that are the 'bane' of HDMI are not the maufacturer's (ie: Cary) fault, but are the end result of requirements of the HDMI standard (that are not being effectively or adequately met).
More Good News: the latest/current production run of the Cinema12 (being shipped from NC) features no less than 20 software/firmware fixes and a redesign of the microprocessor pcb to meet new soldering standards at lower temperatures, with pcb trace redesign and other improvements.
in other words, the latest production version has resolved numerous 'odd ball' problems, including heat containment issues in rack installations, and much more."