Try opening the documents using Neooffice. I sometimes find it does a better job handling MS Office files from Windows than MS Office for Mac does. After all .docx and .pptx are nothing more than Microsoft's bastardization of the Open Document standard that is Neooffice's / Openoffice's native format. Apple's Pages is good with .docx files too, but Neooffice is free and Pages is not.
"All you've got to do is own up to your ignorance honestly, and you'll find people who are eager to fill your head with information" --Walt Disney
