[Cooker] Error wehn adding media to URPMI

[Michael Lothian]

I get the following error message:

[EMAIL PROTECTED] fireburn]# urpmi.addmedia main 
ftp://ftp.mirror.ac.uk/pub/Mandrake_Linux/Mandrake-devel/cooker/i586/Mandrake/RPMS 
with ../base/hdlist.cz
unable to take medium "main" into account as no list file 
[/var/lib/urpmi/list.main] exists
added medium main
examining synthesis file [/var/lib/urpmi/synthesis.hdlist.plf.cz]
computing md5sum of existing source hdlist (or synthesis)
examining MD5SUM file
examining synthesis file [/var/lib/urpmi/synthesis.hdlist.main.cz]
examining hdlist file [/var/lib/urpmi/hdlist.main.cz]
Can't use an undefined value as an ARRAY reference at 
/usr/lib/perl5/vendor_perl/5.8.2/i386-linux-thread-multi/URPM/Build.pm 
line 387.