I'm using SM 1.4, I get this entry as well:
L 02/15/2010 - 01:19:51: SourceMod error session started
L 02/15/2010 - 01:19:51: Info (map "c3m2_swamp") (file "errors_20100215.log")
L 02/15/2010 - 01:19:51: [DefibFix] Player NOT FOUND
L 02/15/2010 - 01:27
0: Error log file session closed.
From using it last night it seemed to be working fine. Defibing ppl worked properly, dead bodies were staying where they should, but it was only one night, need more time. Going to post back in a couple days.