IIS 6.0 site - Cannot find server or DNS Error

Migrated 10 websites from IIS 5.0 all respond and work fine. One problem site.

All sites run in a 2 node IIS 6.0 NLB, use Host Headers defined to DNS. No
local host file entry conflict, host header in question responds via ping
from local servers and clients pc's. App Center 2.0 SP2 runs on both
servers.
IPCONFIG /Flushdns was issued but problem persists.

All sites were migrated using IISMT 1.1 utility, problem site was completely
deleted and remigrated and same problem occurs

When attempting to test the site I receive the error,
"Cannot find server or DNS Error"

I reviewed the metabase.xml file proper site definitions all looks fine.
Any ideas on what else could be the problem??

Thanks,
David