Unfortunately, using the Toast Media Browser did not remedy the problem. Although I think I may have isolated the problem.
When I come across a disc that is not found in Gracenote/CDDB (iTunes shows no identifying data), I submit the metadata through iTunes by selecting “Submit CD Track Names…” from the menu. I need to wait a few days for the data to be processed by Gracenote: (http://support.gracenote.com/articles/Public_FAQ/Submit-CD-iTunes-12/?l=en_US&c=Public%3AConsumers&cu=1&fs=ContactUs&pn=1)
I re-insert (or mount) the disc, then attempt the process again through the Toast Media Browser, Toast It, or dragging the disc to Toast Titanium. Often times, the data is NOT found, and the multi-day process begins again until the data is populated in Gracenote.
Curiously, if the data is not in the Gracenote/CDDB database, Toast Titanium freezes during the retrieval process and is not accessible until I perform a system reboot. This is too time consuming to be practical. Time to find an alternative.
Thank you very much for your suggestions, they helped greatly in investigating further.