Use mainscreen if we can't get the window's screen. Might not have any effect though. 
Use mainscreen if we can't get the window's screen. Might not have any effect though. 

git-svn-id: cb3fc60f0f557b927b8032d8a94e869b6f9f230b@1665 0fceea05-a30d-0410-8a8b-80ef821fb0a1

camillobruni/skim,camillobruni/skim,jasongrout/skim,camillobruni/skim,camillobruni/skim,jasongrout/skim