Check in the pbpower.dat file. Make sure that there is not an extra newline character at the end of the file. I had this problem with my server - i had a newline character there, and it was placing a blank line in between the current power slot and the newly inserted one, and then when PB restarted it wouldnt read past the newline and would not remember the latest additions.
Easiest fix: Add his power. Rename the .dat file to .txt. Edit the file, remove the blank line that is in there, and any duplicates that occur of the inserted power. Save the file, rename to .dat. Then either do a server restart or a pb_sv_restart. Then your problem should be fixed!