apache2 segmentation fault (11)

[sgala.matteo]

I'm experiencing in a server with Debian Squeeze and Plesk 10.4 a random apache crash:

[Thu Aug 30 18:49:28 2012] [notice] child pid 13717 exit signal Segmentation fault (11)
[Thu Aug 30 18:49:30 2012] [notice] child pid 12402 exit signal Segmentation fault (11)

Seems that these error happen randomly and only if some user is accessing to a directory protected by htaccess.

If I restart apache the problem disappear for some weeks. And randomly return...

I read that also another guy had a similar issue:http://thegioinguonmo.com/web-server/apache/auto-restart-apache-on-segmentation-fault-error.html

ideas?

Thanks

Matteo