Vbxler,
a) I opened your project.
b) the same problem occurs: folio 3 is shifted greatly to the right.
This is true even after I invoke CNTRL + 9.
c) I created a new (fifth) folio, 5/5.
I then copy-pasted the content of folio 3/5 into folio 5/5.
The identical problem appears then in 5/5.
So this seems to confirm that there is something strange about the specific content of folio 3/5.
If I encountered this problem in a typical CAD software (such as AutoCAD), I would suspect a 'stray' drawing entity located outside the drawing border area, causing a zoom/extents to zoom out far enough to encompass the stray entity.
QelectroTech is not CAD however, and I do not have a guess what may cause this problem.
I hope this may help in a small way.
I regret that I have no answer.
(I am using QeT ver 0.80 in Ubuntu Linux)