Fix for bug introduced in commit
1fdcc70515cdb917fe620aeba216824dcd0c0643. IDE is throwing following
exception...
System.NullReferenceException: Object reference not set to an instance
of an object
at MonoDevelop.Components.Docking.DockBarItem.<Present>m__2 ()
[0x00027] in
main/src/core/MonoDevelop.Ide/MonoDevelop.Components.Docking/DockBarItem.cs:278
at GLib.Timeout+TimeoutProxy.Handler () [0x00000] in <filename
unknown>:0
Merge pull request #667 from johnthom/master

Fix for bug introduced in commit