[Koha] Error in 3.8.4

[Robson Galluci]

Hi.
 
We have upgraded from 3.8.2 to 3.8.4 (on Ubuntu, through apt-get) and since then we are experiencing search problems; even after reindexing zebra many times, we keep getting "No results found". We go on reindexing until it eventually works, but sooner or later the problem is back. Our library has 50k records. The log says: [Fri Oct 05 16:03:31 2012] [error] [client ----] [Fri Oct 05 16:03:31] detail.pl: Use of uninitialized value in string ne at /usr/share/koha/intranet/cgi-bin/catalogue/detail.pl line 260., referer: http://xxx.xxx.xxx.xxx/cgi-bin/koha/catalogue/search.pl?q=xxxx And detail.pl line 260:
if ($item->{'materials'} ne ''){
	$materials_flag = 1;
}
push @itemloop, $item; Any suggestions? Thanks in advance.