[Koha] Can't call method "as_usmarc" on an undefined value at /usr/share/koha/lib/C4/Search.pm line 2388.

Hi! Could someone help me? After I had cataloged my books, I did a search, on Intranet. Koha showed me a list with all my cataloged itens. When I clicked on page 2 of the list, I had the error: *Can't call method "as_usmarc" on an undefined value at /usr/share/koha/lib/C4/Search.pm line 2388. * I'm using Koha 3.00.06 and I googled it and this problem occurs on: http://library.gretsauniversity.ac.ke/cgi-bin/koha/opac-search.pl?q=au:Hill%... , but in OPAC. What should I do to fix it? Thanks in advance, Geovana.