So I sould start with the usual first post disclaimer: I did search for this and did not find a general bug report thread but I appologize if my noob status and the fact that I am posting from my phone have combined for an error in etiquitte.
I have used the preview on three phones now and all have the same problem. If you download songs to the phone you get a notification in the notification bar that tells you x of xx songs downloaded. But even when all songs have been downloaded the notification does not go away. I would post a screen shot but that does not seem to be an option, at least not from the mobile view.
The phones have all been unlocked GSM Galaxy Nexuses running ICS builds. The current version is 4.0.4 but one of my tests was on build 4.0.3.