gridscreen after roposterscreen

hie i was trying to make an app which will open a gridscreen after clicking on an image from the roposterscreen and after selecting an image from that gridscreen another gridscreen2 will open.But after selecting the image from the roposterscreen, the 1st gridscreen is getting displayed only for just a second and it is closing.I am getting an "invalid" roGridScreenEvent .is it possible to open a gridscreen after roposterscreen.waiting for replies.