I also have a Panasonic Viera TV, in my case model number TH-42PZ8ES. FYI, it has 2 x HDMI, 2 x SCART (AV1 & AV2 of which AV2 supports S-Video), 1 x Composite & 1 x S-Video on the front panel (both of which share the AV3 input), and 1 x Component. See pics below. Anyhow, just updated to version 1.1.39 and it seems to work much better than the 1.1.37 build, so I think you're on to something, Copernicus

Testing with the "1b" preset the 1.1.39 build properly switches between AV1-AV3, HDMI1-HDMI2 but not to Component. As the "Antenna" button (I assume supposed to switch to analogue TV) was disabled, I couldn't test it out.

For reference, I took a few photos which might or might not be helpful, see attachments:
1. List of inputs available -- note that for AV2/AV3 you switch between "regular" and S-Video mode by pressing right and left (see the two boxes on the right).
2. Back panel showing input ports.
3. Front panel showing input ports.
4. Remote control, where the two buttons to the top-right control input -- "TV" switches between analogue & digital TV and "AV" brings up the list of inputs (pressing it repeateadly cycles through the list).

I really appreciate the continued development on this by the way, it's one of the most useful applications for the N900 in my opinion. Wish one could somehow crank the IR transmitter up a few watts in power, but that's probably not going to happen