This really can't be overstated. Proper name resolution is integral to successfully using PDQ Inventory. If you manage your DNS server(s) it really helps to perform basic housecleaning (like scavenging old records, consolidating or deleting old zones, etc)
If you've seen errors such as Target Name Mismatch, Failed To Connect to ADMIN$, The Target Account Name Is Incorrect or other messages that basically state that a computer or target couldn't be reached then you may have a DNS issue.
Some good reading material on the subject:
http://technet.microsoft.com/en-us/library/cc731991.aspx (for DNS on Windows 2008)
http://technet.microsoft.com/en-us/library/cc755960(WS.10).aspx (for DNS on Windows 2003)
http://technet.microsoft.com/en-us/library/bb726934.aspx (Originally written for Windows Server 2000 but still has relevant troubleshooting tips)