Did you ever figure out how to get the "sync device" button to show up on the toolbar? I am having exactly the same problem, with MM 4.1.10 on Windows 7.

FWIW I received a SGS2 yesterday, and was extremely pleased with how easy the sync process was with MM4. Plugged in the phone, a little bit of configuration, and I was off. Synched a heap of flac files, playing them in PowerAmp, loving it! Goodbye transcoding, goodbye parallel mp3 libraries, goodbye iPod!

I still have a few wrinkles with the UI - I haven't figured out how to get a (working) sync device button on the toolbar instead of going through menus, but if that's the worst problem then I'm laughing.

This is on Win 7 64 bit; what platform are you guys on? As Lowlander points out, without knowing your setup reproducing or fixing any problems will be nigh-on impossible.

I'm getting much the same mileage on my Droid Bionic... It's very inconsistent... sometimes it will sync correctly (though the final step -- which appears to be where it writes playlists -- takes a long time). Other times, it hangs completely or gives errors. I've had some limited success (enough to make it workable) by restarting both the phone and the PC, and then syncing, but it's quite frustrating. Sometimes it will also delete all the playlists or create playlists with duplicate names with one of each being empty.

At this point, I'm syncing some 1800 files, but I was having the problem before with a playlist of less than a hundred as well. It does seem more frequent with the larger playlists, though...

I spent 7 hours yesterday evening trying to sync music to my SGS2.

I thought it was just being incredibly slow - but actually, you are right, it just hangs every few minutes. Towards the end I thought it had completed, but no...I still I have individual tracks showing as playlists, around 4 duplicates per song and not all albums transferred.

I don't know what to do. I'm desperate to get this sorted out. Please can someone help us sync our phones!

I have the same problem. Also when it does complete the sync it only copies certain songs. I am trying to copy song via send to card option to see if I have better luck. I always get the MTP syc error and have to reboot phone.

Apart from playlist issues, I now have a problem with syncing files to the phone via MTP. The bar at the bottom of the screen is full to the right (indicating that copying is complete) but the process hangs with the status reads "Synchronizing". The only fix is to disconnect the USB cable and reboot the phone.

I should have stayed with MM3.