[Koha] Sudden trouble with 2.2.9 Z39.50?

[Marty]

Koha 2.2.9 has been running quite nicely for me now (as opposed to koha 3, I haven't succeeded in running it succesfully yet), but suddenly I get this popup when I do a Z3950 search that says 'you have chosen to open search.pl which is a .PL file (duh) from http://debian:8080 What should iceweasel do with this file?'

It always worked fine, I do have a functional internet connection, and I am really puzzled... Any ideas?

output from koha-error_log
[Fri Apr 24 23:55:44 2009] [error] [client 127.0.0.1] Premature end of script headers: search.pl, referer: http://debian:8080/cgi-bin/koha/z3950/search.pl?oldbiblionumber=&isbn=0764203266