I recently had the odd situation where trying to connect to a shared printer on a Windows XP workstation, a member of the AD domain, did not work. It failed to connect. However, connecting using the IP address of the host worked just fine.

DNS entries were all registered correctly for the netbios name, and pinging the host from the server resolved it just fine. No firewalls were blocking file/print sharing ports, file and print sharing was turned on...

After 30 minutes of verifying the usual suspects, I was ready to tear out the hair on my scalp. Fortunately I had a bright moment and actually read the error message - it referenced something about time not being correct. I looked at the server's time and then the workstation and alas - the workstation was set 1 day earlier. Once I fixed the time on the workstation I could access it using its netbios name once again.