I exported mix as wave file using from Export Control Bar module. Sound is OK but it ignored area selection.
So I selected the "Selection" on the Export Control Bar module and then exported it. Area selection is not ignored but there is no sound. (Getting flat line wave file. Length is OK.)
I'm making anything wrong?
 
[resolved maybe]
After relaunch CbB, it seems working well.
It's weird... I believe my operation is perfectly same.

Solo any tracks?

No Solo tracks.
If export from File menu > Export > Audio, it's all OK.

After relaunch CbB, it seems working well. My operation is perfectly same.
It's weird...

The new export bar is OK, but I find that it doesn't give the option for dithering, making it less useful.  Am I missing something?

Look under the advanced tab. I really like this new feature btw.