Its possible a specific file is causing the problem. First, format the device, then try transferring a few files to the device. unplug the device and see that you are successfully completing the refresh database.
Then add a few more folders till you find the file that is causing the problem.
Make sure your firmware is updated to the latest version (1.01.29), there are instructions on how to do it at the top of the forum.
I had this problem big time with my 1st two sansa clips last year. I deduced it to a PC problem as it worked just fine in both MTP and MSC modes on my laptop, but the clip would always freeze when refreshing database. Prior to that, I could not even get WMP11 to see the clip unless in MSC mode. At the time I attributed the problem to what I considered a worthless transfer protocol (and still do in some ways).
Try it on another PC and make sure you have the lastest fw. Personally, I wouldn’t bother w/ the fuss of whether or not an improper ID3 tag was causing the error. If the problem is fixed, then you know it is the PC. I was past due for a reformat anyway… but definitely didn’t reformat just for the clip. I am glad I gave the clip a 3rd chance afterwards though. I absolutely love the device. Now it’s just a matter of explaining to the naive how a $60 device is superior to an iPod.