该问题只发生在Receiver3.4版本，Receiver3.3以及之前版本，包括Online Plugin都不存在该问题。
当升级到Citrix Receiver 3.4以后，连接后端XAU服务器，画面很慢。这是由于，在Receiver 3.4版本中引入了一些新的特性，导致画面的刷新和缓存模式的默认行为发生了变化，虽然可以更好的配合新产品，但对于XAU这种很久为更新的产品而言，出现了使用问题。
修复方法：
设置DeferredUpdateMode值为False
1 2 | x64: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\ICA Client\Engine\Lockdown Profiles\All Regions\Lockdown\Virtual Channels\Seamless Windows\DeferredUpdateMode {REG_SZ} x86: HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\ICA Client\Engine\Lockdown Profiles\All Regions\Lockdown\Virtual Channels\Seamless Windows\DeferredUpdateMode {REG_SZ} |
DeferredUpdateMode
Enables or disables deferred screen update mode.
Add this value and the ForceLVBMode value to the [WFClient] section of the Appsrv.ini file located in the user’s profile directory on the computer running Citrix XenApp to address repaint issues due to a poor refresh rate. This may occur with some applications when running the application in seamless mode while utilizing the pass-through client on the server.
