This bug is probably along the same lines or even directly related to the bug where objs must be deselected after unlinking and reselected to manipulate.
This one is where you have several objs linked. you single select one of the obj and unlink, select another single and unlink, move the two objs to a different position separately. Ctrl-click to select the other obj you moved so that now you have both of them sleected and hit ctrl-L to link. Here is the bug:
Once these two objs are selected, you hit ctrl-L to link, one of the objs sometimes jumps .3m away from the other. When relinked the same obj keeps moving .3m away. ONly way around this I've noticed is to link one of the objs to something else, then drag the jumping obj over and link it with the obj you tried to in the beginning. Then unlink the extra obj you linked the first one to.
Hope this is clear as mud. Doesnt happen every time and may be due to packet loss as well.