Version:           1.5.5 (using KDE 3.5.5, Kubuntu (edgy) 4:3.5.5-0ubuntu3.1.1)
Compiler:          Target: i486-linux-gnu
OS:                Linux (i686) release 2.6.17-11-386

Simply create a new diagram in an empty project.   The new diagram will be added in the UML model but the central/drawing pane will be frozen (i.e does not refesh its content).

Note that when I start umbrello from the command line, I receive the following X errors: 
X Error: BadDevice, invalid or uninitialized input device 166
  Major opcode:  144
  Minor opcode:  3
  Resource id:  0x0
Failed to open device
X Error: BadDevice, invalid or uninitialized input device 166
  Major opcode:  144
  Minor opcode:  3
  Resource id:  0x0
Failed to open device