Apache2 Segmentation fault / PHP54

[FabD [ML]]

Hi,

Since I use PHP54 (instead of PHP5 port), I've sometimes an error in
Apache2 log like that :

[Thu May 31 10:32:07 2012] [notice] child pid 1239 exit signal
Segmentation fault (11)
[Thu May 31 10:32:52 2012] [notice] child pid 1246 exit signal
Segmentation fault (11)
[Thu May 31 10:33:32 2012] [notice] child pid 1241 exit signal
Segmentation fault (11)

It's always appears when I submit a form (there's no response, the
process fails).

I'm wonder which way I can explore to know more about this error.
What's the real cause ?

This error stops if I stop et restart Apache2.

Thanks,

Fabien