backingstore option for xwin

[Marco Bruschi]

Hi,

I'm trying to start xwin for kde3 on cygwin with the additional option 
+bs. ie:
start XWin -noreset -ac -nowinkill  +bs %1
The result is that I get indeed the backingstore in all the opened 
windows, but there is a very long persistence of the windows themselves 
when I drag them.
Do you know any additional option in starting XWin that could override 
this problem ?
To start kde3 on cygwin I'm using the  script /opt/kde3/startkde.bat.

Thanks a lot.