checkdnsrr on WIN NT and IIS

Having a few problems with the checkdnsrr command under Windows NT and IIS. The following code <?php if (checkdnsrr('creed.co.uk','ANY')) {echo "foo";} if (gethostbyname('creed.co.uk')) {echo "bar";} ?> only gives the result "bar" Any variation I try of checkdnsrr doesn't seem to work. I'm trying to use the command to validate email addresses in forms, but even though I can get the host name, it refused to believe their is a dns entry? Doing a normal NS lookup shows the domain in question has got MX records. <nslookup:creed.co.uk/*/158.152.1.58> Non-authoritative answer: creed.co.uk NS 12954 ns1.netnames.net 212.53.64.60 creed.co.uk NS 12954 ns2.netnames.net 212.53.77.28 creed.co.uk MX 21556 10 relay1.netnames.net creed.co.uk MX 21556 20 relay2.netnames.net creed.co.uk SOA 21589 ns1.netnames.net hostmaster.netnames.net Serial 1 Refresh 10800 (3 hours) Retry 1800 (30 minutes) Expire 3600000 (41 days) Minimum TTL 21600 (6 hours) Authority: creed.co.uk NS 12954 ns1.netnames.net creed.co.uk NS 12954 ns2.netnames.net NSLookup normal completion. Any pointers as to where I'm going wrong or workarounds if its a WIN bug? Regards Andy W