I backed up a few tracks from my PSP, and then deleted them from my PSP. Just using a USB cable. It was behaving a little weird at first and I had to reboot my PSP to transfer the files. Despite having the .dat, samples and everything, one of the songs just loads up with a blank song screen but the other ones were fine.
Has anyone ever had something like this before? Is it possible to salvage my file somehow? 
I tried running it on PSP and Windows.