I just upgraded the CoverArt plug-in to version 2.3.1.1. However, I couldn’t upgrade from version 2.3.1.0 (the Upgrade button was ghosted). To upgrade, I first had to roll back to version 2.3.0.3.
I doubt it matters, but I also have the following plug-ins installed;
Chocolate Theme 0.1.2.0 (in use), Diamond Theme 0.3.4.0, IBN People Provider 1.0.4.0, MediaInfo Provider 1.2.0.7.
There is a known bug in configurator which allows you to install CoverArt versions intended for Titan beta. This will be fixed in Titan. The latest version usable in Draco is 2.3.0.3