Last week I was troubleshooting extremely slow network performance on Citrix XenServer 6.02 installed on HP Proliant BL460C G7. The solution was based upon Citrix Provisioning Services 6.1 and Citrix XenApp 6.5 with all hotfixes.
You might ask why not run XenServer 6.1? The customer did a Citrix XenServer Rolling Upgrade to 6.1 and a Provisioning Services Target Device software upgrade.
After the upgrade was completed they where experiencing problems and who would even think that Citrix XenServer 6.1 does NOT support Provisioning Services or XenDesktop. The XenServer Tools Workaround for XenServer 6.1.0 did not work in this environment.
Today Citrix acknowledges that some customers are experiencing intermittent Windows issues with XenTools in the XenServer 6.1 release. Hotfix (XS61E005) for all XenServer 6.1 installations will be released in early January 2013 and support PVS 6.1 (but what about XenDesktop?).