hi,
I can't reproduce that, what version are you using ?
the only moment where a coordinates could be 0 is if the point and the object's pivot are sharing the same coordinates AND you have the "Enable Axis" enable.
(or you are in object's rel or abs coordinate and the point is at the same position of the pivot's object.
As if you were at the same time in object's mode and in point mode. (moving the object's pivot point and the modeling axis at the same time)
So this look like a bug.
by the way, what do you call the "default state" ? The last modeling axis position ? the position when you selected the polygon ?
Cheers,
Manuel