>> This does not happen with current xpra v1.0.3-r15051 from xpra repository. >I have to correct myself: Now it happens with xpra v1.0.3, too. I'm not sure why I didn't have the error the first time I checked this.
Update: xpra v1.0.3 only has problems in virtualbox with guest additions installed, similar to X/xinit (#856662). Otherwise, it is ok.