Why VNC server crashes when client disconnects?

[Yuri]

I used vnc while ago without this problem.
Now I see that when client gracefully exits (window close) server 
crashes with exception:
terminate called after throwing an instance of 'rdr::EndOfStream'
knotify: Fatal IO error: client killed
kwin: Fatal IO error: client killed
ksmserver: Fatal IO error: client killed
kaccess: Fatal IO error: client killed
....


Is this something temporary, or somethig's wrong with my system?

vnc-4.1.3_2 on vnc-4.1.3_2

Yuri