--- Operating System, Graphics card ---
osx 10.8.4, mbp 6.2, 8gb ram, gt330m

--- Blender version with error, and version that worked ---
2.69rc1, own r60721M

--- Short description of error ---
in terminal of official on reload startup.blend (ctrl+n):
Memoryblock free: pointer not in memlist
Memoryblock Data from NT: double free
Memoryblock lib block: double free

no crash there.

if i quit blender:
Error: Not freed memory blocks: -99


own build crashes on ctrl+n:
blender(4091,0x7fff7df56180) malloc: *** error for object 0x10bc70da0: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug
Abort trap: 6


--- Steps for others to reproduce the error (preferably based on attached .blend file) ---
download startup.blend
open it
save it as your startup
hit ctrl+n
see console