[Libreoffice] PPT/PPTX created by LibreOffice RC2 can't be opened by MS PowerPoint Viewer and MS Office Web Apps.

Hello! I use LibreOffice in my daily work, but I have to exchange documents with MS Office formats 
(mainly .doc/.xls/.ppt) because all others use MS Office (mainly 2003). So I pay very much 
attention to try to reduce incompatibility at the utmost.


Today I found a problem which LibreOffice has but OOo/Go-oo don't have. The .ppt/.pptx documents 
created by LibreOffice (I use RC2) can't be opened by Microsoft PowerPoint Viewer (with the support 
of 2007 formats) and Micrsoft Office Web Apps. MS PowerPoint Viewer says that the documents have a 
problem; MS Office Web Apps warns that the .ppt documents have a potential security problem and the 
.pptx documents are broken. However, MS Office PowerPoint can open these documents.


The .ppt/.pptx documents created by OpenOffice.org/Go-oo can be opened by both of MS PowerPoint 
Viewer and MS Office Web Apps without any warning.


LibreOffice RC2 has an other problem about converting an .odp document to a .pptx document. An .odp 
file of about 500 KB is saved as a .ppt file with the similar size, but it will be saved as a .pptx 
file with more than 6 MB. Perhaps this is why MS Office Web Apps says the .pptx documents are 
broken.


I wish that the problems will be solved in the next release.


Thanks for all people's efforts to launch and improve the great project!