UltraVNC

I look the ultravnc source code and analysis the hook mode, i want to ask that the UIPI in window vista and 2008 will be affect the vnc,so in ultravnc ,uses trigger_event array instead, is that reason？ any one knows，thanks

is ultravnc use the hook mode in window server 2008? i found from the internet that " VNC will be slow if the screen capture method is set to os hooks on Vista and 2008, especially the 64 bit versions.
Selecting "poll screen" for changes makes a big difference."

if ultravnc do not use hook ...