I have noticed that certain channels that output digital sound (presumably Dolby Digital) cause my preamp to jump into a different mode (THX Ultra2) in which I can't hear the Tivo sound effects (bings and bongs). The sounds don't seem to come back until I get to a channel or screen that jumps back to the default mode (ProLogic IIX Movie Mode in my case).
I assume this is normal and unavoidable. I take it that the bings and bongs just aren't added into the digital feed? Anyway have a work around (not that it's a huge deal)?