This has had various problems with compatibility. Recently, the task bar has remained on top, blocking text and important mail feature (for instance, the reply etc. button). I've been patient waiting for upgrades and corrections, but I finally disabled the extension today. The extension is a great idea and I like the features (especially one-click addition to the list from an email message), but at the moment, problems are outweighing the benefits. I may try it again in a month or so.