We have about 7-8 Sun Ray 3 thin clients each running from its own Win 2008 R2 server. When browsing a Windows 2008 file server, there are random delays and sometimes timeouts resulting in a network permission denial error. When the communication doesnt lockup (let's say 10 clicks before a random latency probem), the latnecy is nil and speedy as anything. The older thin clients coming from either a S2000 or S2008 server have no issues reading/writing to this same S2008 file server. The issue is only when the server is accessed from these newer 2008 R2s. It isn't a NIC problem as the issue is consistent across all of the R2 servers. S2008+ do not authenticate using NTLM? So I cannot see it as anything to do with NTLM settings. It would strike me as an SMB issue except for the fact that all S2008+ use SMB2... so this shouldn't be an issue either. I really don't think it is McAfee but I guess AV is always a possibility. Any ideas?

Hello, please see the following article from Ace Fekay about known problems: http://msmvps.com/blogs/acefekay/archive/2009/08/20/tcp-chimney-and-rss-features-may-cause-slow-file-transfers-or-cause-connectivity-problems.aspxBest regards Meinolf Weber Disclaimer: This posting is provided "AS IS" with no warranties or guarantees , and confers no rights.

Thanks for the suggestion Menolf, unfortunately the problem persists. Disabled The RSS TCP Chimney Offload features to no avail. More info: (7) Server 2008 R2 and (8) Sever 2008 in the same domain. No issues when going from any s2008 -> s2008 R2. The other direction is where there are problems. I can ping a s2008 network share from an s2008 r2 any size packet for any length of time and receive 0 latency or timeouts. But when navigating the files/folders there is eventually a 30-60 second delay or a timeout error in the form of a permission denial.