I must have been unclear. Not the transformation of the objects is a problem, but the transformation of ANY of the parent (enclosing) objects. This includes any group the objects are in and presumable a transformation of the whole document as you describe as well.
To undo the problem you are seeing (which cannot be solved by grouping/ungrouping), try using the XML editor and removing any transform-attributes on the layer/root nodes.
I must have been unclear. Not the transformation of the objects is a problem, but the transformation of ANY of the parent (enclosing) objects. This includes any group the objects are in and presumable a transformation of the whole document as you describe as well.
To undo the problem you are seeing (which cannot be solved by grouping/ ungrouping) , try using the XML editor and removing any transform- attributes on the layer/root nodes.
Martin