On Dell Server the mouse position is incorrect if RMX is used. The obvious fix is to disable RMX on Dell Server. I'll attach a patch and commit it to CVS.
Created attachment 2782 [details] [review] Don't use RMX if we are Dell Server
Fixed in CVS.
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.