Site visible but 500 server error

Coudl anyone suggest where I should look next.

The site appears to be running pages appear, you can log into manager etc,
but the server is giving out a status code of 500

This was the result of the header check:
HTTP Status Code: HTTP/1.1 500 Internal Server Error
Date: Mon, 30 Jun 2008 13:54:54 GMT
Server: Apache/1.3.41
X-Powered-By: PHP/5.2.6
P3P: CP="NOI NID ADMa OUR IND UNI COM NAV"
Cache-Control: private, must-revalidate
Set-Cookie: SN4867c7711ba21=hmi4iqpht45btfq51gl4mjfhm4; path=/
Set-Cookie: SN4867c7711ba21=hmi4iqpht45btfq51gl4mjfhm4; path=/
Connection: close
Content-Type: text/html; charset=UTF-8

Have tried removing .htaccess but still seems to do the same.
Also have upgraded to 0.9.6.1 p2

Has anyone seen this behaviour?

Thanks

Mark

Yes, there was a bug in recent releases in the SearchHighlighting plugin; disable this plugin and confirm the 500 error goes away.

Ah that’s it!

Have disabled it and now running OK

Thanks very much!