This looks very similar to SuSE bug #246421 (https://bugzilla.novell.com/show_bug.cgi?id=246421) which is fixed in version 2.0.0 of the nv driver. It's a one-line patch, http://gitweb.freedesktop.org/?p=xorg/driver/xf86-video-nv.git;a=commitdiff;h=90c53c5322e50bce06996e3c857e6bf7531235d4 so it could easily be backported (I'll try that).