Apache child pid segfault + APD

I recently installed APD to help profile some code that I've written,
and noticed that whenever I run it (with apd_set_pprof_trace() at the
top) I get these errors in my apache logs.  I spent awhile looking at
different sites, but even recompiling PHP + Apache didn't help.
Anyone seen this before?

[Fri May 02 21:20:56 2008] [notice] child pid 13818 exit signal
Segmentation fault (11)
[Fri May 02 21:40:08 2008] [notice] child pid 14820 exit signal
Segmentation fault (11)
[Fri May 02 21:40:08 2008] [notice] child pid 15027 exit signal
Segmentation fault (11)
[Fri May 02 22:00:08 2008] [notice] child pid 16081 exit signal
Segmentation fault (11)
*** glibc detected *** free(): invalid pointer: 0x0000002a9956d000 ***
[Fri May 02 22:00:10 2008] [notice] child pid 15273 exit signal Aborted (6)