connectors are misplaced when objects it connect to are ungrouped

[Jelle Fresen]

Inkscape version: 0.48.4 r9939
OS version: Windows 7

1) Connect a circle A and an arbitrary object* B with a diagram connector
2) Group A with any object except the connector itself
3) Ungroup the group created in step 2
4) The connector is now rendered between the origin and B, or not at all if A was grouped with B and B is a circle.
5) Moving one of the two connected objects restores the correct rendering of the connector.

* I haven't searched extensively to other shapes that trigger the same bug, but my preliminary findings are that at least one of the two objects needs to be a circle. (Tried rectangles, polygons, 3D boxes and spirals)

The bug looks to be related to bug #556467

In case there are more parameters that influence the bug, I attached an example in which the bug will be triggered if one of the circles is used as object A.

[su_v (suv-lp)]

Reproduced with Inkscape 0.48.4 on OS X 10.7.5,
not reproduced with Inkscape 0.48+devel r12419

Testing with archived builds:
- reproduced with revision <= 12004
- not reproduced with revision >= 12005

Not sure what to make of this, but apparently this was fixed as a side-effect of
<http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/12005>
for otherwise unrelated bug #1005085.

@JazzyNicco, @apenner - can you confirm?