I originally received this report from someone in Japan via private email. He also told me that, in order to reproduce this bug, you need to first install the patch for KB2289187
but I haven't verified that this step is necessary.
Anyway, here are the steps to reproduce:
1. Open Impress, and create a new empty presentation document.
2. Insert two arrow objects (but in theory any drawing objects will do).
3. Select and group them.
4. Save as .ppt.
5. Now, try opening that file in MS PowerPoint. The grouped objects are entirely gone.
This one is for Thorsten.
Thorsten, given how common grouped objects are in presentation in general, I wonder whether this should be considered a release blocker for 3.3...
Actually, PowerPoint won't open any document that contains grouped objects...
I saw something curious:
During my first tests the problem was reproducible with "LibreOffice 3.3.0 RC1 - WIN XP German UI [OOO330m17 (build 126.96.36.199" and MS PPT VIEWER, Viewer was not able to open .ppt from LibO with grouped objects. Opening .ppt with OOo3.1.1 and saving again healed the problem.
Then I did some further tests, and now suddenly my viewer opens all .ppt from LibO with grouped objects without problems. Strange!
Looks like we got this bug from Oracle.
Apparently they have already fixed it for their 3.3 version.
Here is some more info on this bug.
Cherry-picked fixes from OOo.
Closing - Sophie