Global Undo occasionally turns itself off for no apparent reason

Technical Support Basics & Interface
1

Sometimes when I hit undo in object mode, it doesn’t work. When I check the Editing tab of the User Preferences “Global Undo” is ticked off. This can obviously be very frustrating, but the really annoying thing about this is that I always turn it on in my User Defaults and even check that it’s on before starting work.

So for some reason, it occasionally gets turned off, but I can’t find out why. There is no pattern to when it happens that I have noticed.

Does anyone else ever notice this problem? I’ve had this happen for several Blender releases and it happens on different computers as well.

2

I have noticed this too. Sometimes I find that I suddenly can’t move an object to another layer as the move layer window is greyed out. That’s the first sign that global undo has turned itself off. The most annoying thing is that when I turn it on a lot of the changes I have made since it turned itself off reverts back. so I can lose a fair bit of work.

I’ve noticed this happening about 4 or 5 times in the last few months.

Blender 2.63 r47553 (64-bit Windows 7) is the latest version of Blender in which this happened to me.