Many thanks for keeping trying to fix this. Yes, it did happen with 1.6.5 but not immediately, maybe 1-2 days after so I didn't link the two. Also, it's a regular installation. I have just updated to 1.6.6 b1 and not seeing the problem anymore - after extensive usage with both via album ID and artist & album name. I'll try your new version, hopefully it doesn't return!.
PS. Now you have the code on your mind, any chance of sorting the Date problem ie option to use the ORIGINAL RELEASE DATE year?