Created attachment 92837 [details]
test document with the drawing described in the bug description

Steps to reproduce:
1/ open a new empty document in LibreOffice 4.1.4
2/ add drawing toolbar
3/ create 2 forms, for example 2 circles
4/ draw a line between these 2 circles
5/ select the line and click on one of its ends, the point becomes red
6/ in the drawing toolbar, click on the Points icon, a new toolbar appears
7/ In this toolbar, click on the button Symetric Transition (idem if you click on Smooth Transition, the purpose is to transform the line in a curve). Now move the point in the middle of the line to transform the line in a curve.
9/ as a witness, draw a line between both circles
9/ In the drawing toolbar, click on the button Select (the first one) and draw a selection rectangle around your nice drawing to select it entirely. Right click and choose Group > Group in the contextual menu.
10/ save your file and exit LO 4.1.4
11/ open your file with LO 4.2.0.3

Current behavior : the curve is not where it should, but the straight line is correct.

Expected behavior: LO 4.2 should not distort the drawing

This bug has been reproduced on MS-Windows and Linux (FR QA mailing-list)

Best regards. JBF