SBS 2008: Cannot resolve certain top level domains

Cannot resolve top level domains like .co.uk. when Windows 2008 DNS Server is configured to use root hints the default.
This is a problem I have noted on a number of SBS 2008 servers about a week after installation. I found that restarting the DNS service cleared the problem for a few days and then the problem would return. The work around suggested at the time was to schedule the restart of the DNS service every day.

Other alternatives included clearing the DNS cache, setting maxcachettl to 2 days or greater, and using DNS Forwarders instead of root hints.
If you want to use root hints set the MaxCacheTTL registry value on the DNS server:

1. Start Registry Editor (regedit.exe).
2. Locate the following registry key:
3. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DNS\Parameters
4. On the Edit menu, click New, click DWORD (32-bit) Value, and then add the following value:
   

   Value: MaxCacheTTL
   

   Data Type: DWORD
   

   Data value: 0x2A300 (172800 seconds in decimal, or 2 days)
   

5. Click OK.
6. Quit Registry Editor. 
7.  Restart the DNS Server service.

This appears to effect all the Windows 2008 range not just SBS 2008.

 Windows Server 2008 DNS Servers may fail to resolve queries for some top-level domains

 Using DNS Forwarders instead of root hints.

1. Open DNS under Administrative tools
2. Right click server name and select Properties.
3. Open Forwarders tab and click the “edit” button.
4. Enter the primary DNS address of your ISP and click Ok.
5. The forwarders section will now attempt to automatically resolve the FQDN for that IP.
6. Click Ok to close the properties window and then close your DNS console.
7. DNS lookups for the TLDs should now be working again. 
   
   If not, stop and restart DNS or give the server a reboot.
   

I noted a suggestion on a blog that entering your router’s IP address in the forwarders section should make SBS look to the router for DNS information. If any one has tried this successfully I would like to know.