BIND9.4.1 : forwarding not working

Hello,
For some odd reasong i setup a forwarder zone a couple months ago and all has been woorking fine, except now. The forward requests sometimes responds with an IP address. Here's a captue from the bind log in debug mode, i hope someone can explain to me what going on? thnx

21-Sep-2011 09:20:47.549 queries: info: client 42.108.20.14#54543: query: CAT01-SR1.whi.ep.ctc IN A +
21-Sep-2011 09:20:47.549 security: debug 3: client 42.108.20.14#54543: query 'CAT01-SR1.whi.ep.ctc/A/IN' approved
21-Sep-2011 09:20:47.549 resolver: debug 1: createfetch: CAT01-SR1.whi.ep.ctc A
21-Sep-2011 09:20:47.549 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): create
21-Sep-2011 09:20:47.549 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): join
21-Sep-2011 09:20:47.549 resolver: debug 3: fetch 308bd6c0 (fctx 30f71968(CAT01-SR1.whi.ep.ctc/A)): created
21-Sep-2011 09:20:47.550 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): start
21-Sep-2011 09:20:47.550 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): try
21-Sep-2011 09:20:47.550 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): cancelqueries
21-Sep-2011 09:20:47.550 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): getaddresses
21-Sep-2011 09:20:47.550 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): query
21-Sep-2011 09:20:47.550 resolver: debug 3: resquery 30f78968 (fctx 30f71968(CAT01-SR1.whi.ep.ctc/A)): send
21-Sep-2011 09:20:47.550 resolver: debug 3: resquery 30f78968 (fctx 30f71968(CAT01-SR1.whi.ep.ctc/A)): sent
21-Sep-2011 09:20:47.550 resolver: debug 3: resquery 30f78968 (fctx 30f71968(CAT01-SR1.whi.ep.ctc/A)): senddone
21-Sep-2011 09:20:47.556 resolver: debug 3: resquery 30f78968 (fctx 30f71968(CAT01-SR1.whi.ep.ctc/A)): response
21-Sep-2011 09:20:47.556 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): noanswer_response
21-Sep-2011 09:20:47.556 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): ncache_message
21-Sep-2011 09:20:47.556 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): clone_results
21-Sep-2011 09:20:47.556 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): cancelquery
21-Sep-2011 09:20:47.556 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): done
21-Sep-2011 09:20:47.556 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): stopeverything
21-Sep-2011 09:20:47.556 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): cancelqueries
21-Sep-2011 09:20:47.556 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): sendevents
21-Sep-2011 09:20:47.556 resolver: debug 3: fetch 308bd6c0 (fctx 30f71968(CAT01-SR1.whi.ep.ctc/A)): destroyfetch
21-Sep-2011 09:20:47.556 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): shutdown
21-Sep-2011 09:20:47.556 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): doshutdown
21-Sep-2011 09:20:47.557 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): stopeverything
21-Sep-2011 09:20:47.557 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): cancelqueries
21-Sep-2011 09:20:47.557 resolver: debug 3: fctx 30f71968(CAT01-SR1.whi.ep.ctc/A'): destroy
21-Sep-2011 09:20:47.557 queries: info: client 42.108.20.14#54544: query: CAT01-SR1.whi.ep.ctc IN A +
21-Sep-2011 09:20:47.557 security: debug 3: client 42.108.20.14#54544: query 'CAT01-SR1.whi.ep.ctc/A/IN' approved

Found out more info.
Apparently 2 of 4 destination nameservers have the A/PTR records. I thought that when you configure a zone for forwarding that it would "round robin" through all the nameservers in the list until it gets a response?