Koha error

The following fatal error has occurred:

Can't call method "fields" on an undefined value at /opt/koha/cpl/opac/cgi-bin/opac/opac-MARCdetail.pl line 117.
Apache Server version: Apache/2.2.3 Server built: Aug 30 2010 12:32:08
Koha 3.00.06.010
Koha DB 3.0006010
MySQL mysql Ver 14.12 Distrib 5.0.95, for redhat-linux-gnu (i686) using readline 5.1
OS Linux localhost.localdomain 2.6.18-194.17.4.el5PAE #1 SMP Mon Oct 25 16:35:27 EDT 2010 i686
Perl 5.010001