After transforming an object any filters and things applied will also be transformed. Sometimes this really isn't what you want atall, and you need to reset the transform to the indentity without moving the vertices. I've seen a few suggestions for getting rid of the transforms, that have variable ease and effectiveness. I can't help thinking there should be a button for it, but I can't find it if there is. This is my solution. It is easy, and so far it hasn't failed me.

Make a new object.
Select your object.
Shift-Select the new object.
Path|Union.
Switch to the vertices view/editor.
Delete the vertices of the new object.

Inkscape (quite reasonably) just gives up on the idea of remembering transforms when you make a union of objects, and applies them permanently to all the vertices instead.

Example use case: Making 4 arrows pointing N, E, S, W by drawing one and then rotating copies of it, and then trying to apply a filter to them which looks consistent for the group as a whole.

Hi.

You can remove the transformation values of paths by that -but what if your object is a text?
Also be aware that by the union, as by with any boolean operations, the paths are recalculated
-overlapping segments get new nodes at intersection points, nodes close to eachother get merged,
new node will appear where the path touches the top of the bounding box, some parts may disappear if it's a compound path,
and each node is moved with about 0,005 pixels.

So, another trick is, to group the object right before the filter is applied.
That way you can transform any objects inside the group after the filter is set too, and can use that on any objects.