DHCP not updating dns when it used to.

We have had DHCP setup to update dns with a domain account and it has been working.  Recently we are getting nearly all DHCP leases with the pen icon and dns is not updating.  There are a few new dns updates but the dhcp register account is not the owner as it should be.  If I delete a computer's dns record and do ipconfig /release then ipconfig /renew.  Nothing populates in DNS.  If I do ipconfig /registerdns on that same computer, a forward dns record appears but not with the dhcp register account as owner and a reverse record does not populate.  When I look in the DHCP logs I see lots of these "DNS update request failed as the DNS update requests queue limit exceeded" entries.  Again this used to work where the dhcp register account would create the forward/reverse dns entries and be the owner.  Any ideas?