TiVo / HDTV audio problems

I own a Toshiba Series 2 RS-TX20 combo Tivo DVR / DVD recorder. I just love it but I just purchased a HDTV ready Sony Bravia LCD TV, I am having a hard time getting all components to work correctly.

With the Digial Cable box, everything worked smoothly but with the new HDTV box it doesn't. The cable guy said that he's not responsible for getting the TiVO/Toshiba box working correctly so he left it as is.

Ok... here's the setup / problem.


Audio: works when set to Video 4 but not on Video 3. Can adjust audio with Toshiba remote or TV remote, but not with Cable remote.
TiVO: only works when set to Video 3 (Anything I record on TiVO has no sound.) Basically I can no longer use TiVO... but can play things previously recorded on Video 3 WITH sound.
Cable Channels: work manually with Toshiba remote on both Video 3 & 4. Better on Video 3.

I went through the setup and plowed through the manuals, but can't seem to figure it out.

I spent about an hour with Toshiba helpdesk and he said that since there's only one audio out connection on the comcast box that the only solution is to invest in a surround sound system. Even then I'll need to toggle between video 3 (tivo) and video 4 (hi def).

Any suggestions or help would be appreciated.

Susan