Q:

slow unc resolution on a win 2008 share

I've got some neworking issues with my sbs 2008 server. Basically if i try and access the server's shares via a unc path it takes a long time to resolve, but a mapped drive is quick (until i try to open a file then very often it can be slow). 
This behaviour even happens on the machine itself if i try and access it's own shares via it's unc path e.g  
\\servername\share\ 

Copying to it or from it once open is as fast as ever, and the behaviour is periodic - it sits for a while thinking then everything bursts into life and is quick, then after a while it is slow again. 
Things to note:
1) I've no virus guard on it (uninstalled it when i started to have trouble). 
2) It is fully patched up. 
3) I've checked the switch by continuous pings and don't lose any. 
4) I've tried disabling shadow copies with no effect. 
5) No backups are running. 
--edit
additional information
1) macs don't seem to have a problem with shares
2) exchange has issues - entourage says it has problems copying an email to sent folder on a mac
3)The server has a Broadcom BCM5708C NetXtreme II NIC
4) TCP chimeny is now off, as is checksum offload is off, large send off load is off. TOE is enabled on the card but can't be disabled unless i turn it on in windows first i think.
5) using the ip address doesn't help.  

A:

Are you using Symantec Enterprise Security 11? There is an issue with 2008 and server shares on older updated versions; not sure if this is your issue but something to look into if you are using symantec (I didn't see any statement about A/V software). 
http://www.symantec.com/connect/forums/mr3-locks-server-2008-file-shares
I noticed this problem on my first 2008 file server after about 20/30 users started using it. It got progressively slower then finally just gave up sharing files but everything else (RDP, etc.) worked fine. After ripping hair out I found it to be the A/V problem stated above. 

