When vncviewer receives a file, the server doesn't respond to messages on the tray icon. Usually it will pop up the menu and then its dead until the file transfer ends. The message loop in vncmenu calls pClient->SendFileChunk() which posts a message back to the same window. So it looks like other messages should be processed eventually. This is all on the same thread, and its normal priority.
Any ideas how to throttle the file messages to allow UI messages to be processed?