Not sure if this is OT or not, but my wife is having trouble with bookmarking as well, but with different symptoms. The playlist in question is the latest Harry Potter book, meaning there are several hundred tracks. The behavior is that sometimes when she chooses "select" bookmark, it instead "updates" the bookmark, meaning she has to traverse the entire playlist to get back to where she wanted to be. This behavior happens only a portion of the time (I don't know how often), but she swears to me she's gotten very careful about picking "select" option and she's not accidently hitting the wrong thing.

I have no idea what version of the firmware she's running. I can find out tonight when I get home, but It was whatever was current in mid January.