[Koha] Bug deleting libraries in preferences?

Hello, In the web installer, i chose importing sample libraries and ended up with all the Midways, Centervilles, etc. While editing the list of libraries via System administration, deleting libraries worked the first few times, but stopped and i can no longer delete some of the libraries. I tried creating some more dummy libraries and i can delete them. Is this a bug? i did not find it on Koha's bugzilla. Thanks and regards, krishnan mani Pune, India Unlimited freedom, unlimited storage. Get it now, on http://help.yahoo.com/l/in/yahoo/mail/yahoomail/tools/tools-08.html/