Kumar> Always the same warning; sometimes it even segfaults python, but Kumar> rarely. I only see it on Mac OS X (two separate machines), python Kumar> 2.4.3 both built from source via Darwin Ports. The same suite gives no Kumar> such warning on a 2.4.3 production machine running Free BSD. In addition to Josiah's response I will note that the warning you get is specific to the Mac's malloc implementation (or maybe more generally to Darwin or *BSD). It's not necessarily that the problem doesn't occur on other platforms, just that the malloc implementation doesn't include that sort of check by default. Kumar> I turned on MallocHelp but just stared blankly at heaps and stack Kumar> options. I've used that stuff but it's been awhile. Try "man malloc" in a terminal window. If that doesn't get you going post your questions pythonmac-sig@python.org mailing list. That's were most of the Mac-head Python developers hang out. Skip