DVD-R single layers appear to be in the only disc that works.

I was also able to get groupings to work using DVD Audio Solo as well (with single layer DVD-Rs).

 

You DID get groupings to work? How did you access the groups in the RDX? I couldn't find any of the songs I put in group 2.

 

I actually did not do anything special in DVD Audio Solo. I just dragged one group of songs into the default group (Group 1), then switched to Group 2 and dragged some songs there as well. After writing the disc, the RDX recognized it without any trouble. The RDX represents the 1st track in the 1st folder as 1-1 on the display. If I skip past the last track in Group 1, the RDX displays 2-1 and begins to play the 1st track in Group 2.

What version of DVD Audio Solo are you using (I just wonder if this feature was somehow fixed in the version I am using...)?

 

I'm actually using DVD Audiofile on the mac. I'll look into DVD Audio Solo on Win.

 

If I borrow a friend's DVD-Audio disc, is there any simple way to copy it so that it plays back in the RDX as a DVD-Audio?

 

No. There's no "simple" way. DVD-audio discs have copy protection. You could copy the DD/DTS tracks and make a new DVD-Audio if you have the right stuff.

Search the TL forum. There is a ton of stuff over there about DVD-A and making your own.