Premature end of script headers



I’ve got a strange problem with Nagios. Sometimes the CGI’s won’t run and when I take a look at the error log of Apache I see the following 2 errors:
[Tue Aug 05 23:03:39 2008] [error] [client] *** glibc detected *** malloc(): memory corruption: 0x080aa340 ***, referer:
[Tue Aug 05 23:03:39 2008] [error] [client] Premature end of script headers: status.cgi, referer:

and sometimes the CGI’s are working correctly. This is in Mozilla as well as Internet Explorer.

I’ve got the following setup:
debian etch 4.03
Nagios 3.03
Nagios Plugins 1.4.12
NDO utils 1.4b7
Nagvis 1.3

Apache and MySQL are installed with the help of apt-get.

I looked at several forums but I can not find any solution. Could someone help me?