Sansa Clip Zip freezing during file transfer

[ursamajor]

Today I had first problem with Rockbox on my Clip Zip. I tried to copy some new music files on my player, but didn't manage to see the content of the two partitions: internal memory and microSD external memory. Just saw the letters (F: and G: in my case) of them in Windows, but not the content. Simultaneously, the player freezed...
A little help? Thanks in advance.

[ursamajor]

I discovered the problem. It was the theme who made freeze the player. Theme "Cleanzip" give some pixel artifacts when start and shutdown the player. I've no idea why, but I just changed the theme and the transfer worked normally.