You have an old version of pike in combination with valgrind 3.x?
cvs log -rHEAD src/pike_memory.h
RCS file: /pike/data/cvsroot/Pike/7.7/src/pike_memory.h,v Working file: src/pike_memory.h head: 1.56 branch: locks: strict access list: keyword substitution: kv total revisions: 56; selected revisions: 1 description: ---------------------------- revision 1.56 date: 2008/01/29 12:02:19; author: per; state: Exp; lines: +7 -1 Support newer valgrind versions