deselecting outside group not working

To get out of a group I normally click somewhere outside the group.

Sometimes this is just not working. The cursor maintains the crossed arrow shape, even outside of the group.

The error can easily be overcome by selecting another tool and the reselecting the select tool. So once you know this, it's not a big problem, just a bit of a nuisance.

I have not been able to duplicate it. Even not in the file in which it just occurred.

An obvious thought might be that I have made the whole drawing inadvertently into a group. This, however, is not the case. Because the cursor retains this cross shape even far away from any object. I also checked the drawing for any "oversized" groups, which is not the case.

System set up:

Windows 7 Ultimate Service Pack 1 64 bits
Inkscape Inkscape 0.91 r13725 64 bits