As I mentioned before in your previous thread, it is most likely an ID3 tag issue. Wrong format, Comments field loaded up with extraneous garbage, excessively large embedded album art, foreign characters are all things that can cause what you are experiencing (delay changing tracks & crashing).
Download MP3Tag and change its Write default (in Tools menu) to ID3v2.3 ISO-8859-1. Then open up your music folders and check for the above-mentioned anomalies, editing as needed. Note you should do this on the copies of the files on your computer, not on your player. Save the edited files, wipe the ones off your player and transfer over the newly edited ones.
