[Koha] z39.50 problem

[Greg Vickers]

Hi all,

Lately the z39.50 lookup process has stopped working for the 
installation of Koha that I look after. (running on Debian stable)

Clicking on the following:
Catalog - Add biblio - Create Empty biblio, insert ISBN number, click on 
z3950 search button

The z39.50 window pops up and only displays the following:
"Z3950 Search Results, Nothing found, Still ?? requests to go"

Here's my z3950-daemon-options file:
# cat z3950-daemon-options
RunAsUser=www-data
KohaZ3950Dir=/usr/local/koha/intranet/scripts/z3950daemon
KohaModuleDir=/usr/local/koha/intranet/modules
LogDir=/usr/local/koha/log
KohaConf=/etc/koha.conf

The weird thing is that the z3950 logs in the LogDir location haven't 
been written to for months.

There are log messages in /var/log/apache/koha/koha-error.log:
210.49.141.186 - - [07/Nov/2006:22:35:39 +1000] "GET 
/cgi-bin/koha/z3950/search.pl?bibid=&isbn=0198507917 HTTP/1.1" 200 1541
query=Select id,file,isbn,title,author from marc_breeding where 
z3950random = ? title= isbn= at 
/usr/local/koha/intranet/modules/C4/Breeding.pm line 167.
210.49.141.186 - - [07/Nov/2006:22:35:42 +1000] "GET 
/cgi-bin/koha/z3950/search.pl?bibid=&random=393126843.57083 HTTP/1.1" 
200 1541
query=Select id,file,isbn,title,author from marc_breeding where 
z3950random = ? title= isbn= at 
/usr/local/koha/intranet/modules/C4/Breeding.pm line 167.
210.49.141.186 - - [07/Nov/2006:22:35:44 +1000] "GET 
/cgi-bin/koha/z3950/search.pl?bibid=&random=393126843.57083 HTTP/1.1" 
200 1541
210.49.141.186 - - [07/Nov/2006:22:35:45 +1000] "GET 
/intranet-tmpl/default/en/includes/common-style.css HTTP/1.1" 200 7431

What do these log entries mean? Does anyone have any pointers about how 
to diagnose this z39.50 problem?

Thanks,
Greg