Plesk's Apache seg faulting

[kerm1t]

Hi,

Out of the blue, my Plesk control panel has stopped working (no page loaded when I browse to it). Looking in /usr/local/psa/admin/logs/httpd_error:

[Mon Jan 15 13:36:48 2007] [notice] Apache/1.3.33 (Unix) mod_ssl/2.8.22 OpenSSL/0.9.7e PHP/5.0.5 configured -- resuming normal operations
[Mon Jan 15 13:36:48 2007] [notice] Accept mutex: sysvsem (Default: sysvsem)
[Mon Jan 15 13:38:11 2007] [notice] child pid 2079 exit signal Segmentation fault (11)

The 'other' copy of Apache (ie the one serving up web sites) works fine.

I haven't upgraded or modified any packages, or fiddled with the config of Plesk itself, so I'm a bit puzzled.

Any thoughts?