[xmonad] xterm/urxvt display problems

[pascal]

Hi

I have a shortcut for launching ncmpcpp (mpd client).
When I use it for the first time in the session, the display is fine.
But when I spawn it again I get some junk display, some areas of the
screen are not refreshed, staying permanently. However if I laucnh
ncmpcpp from an existing *term this problem disappears.
Any ideas ?

My spawn command is :
((modMask, xK_F1   ), spawn "/usr/bin/urxvt -rv -name ziq
-e /usr/bin/ncmpcpp") 

I'm not even sure it's an xmonad related problem

Pascal