PowerPoint Files

[Sgt]

Downloaded PowerPoint viewer 2007. Replaced PowerPoint viewer 2003.
For the last week or so some friends have been sending me PowerPoint files
which will not open error message says as they are not power point files yet
extension is .pps. Up to this point all the power point files I received
from them would open with PowerPoint 2003 and now with 2007 except the ones
I have been receiving the last few days.Thing maybe my virus scanner was the
culprit I disabled it and sent myself one of them, still would not open.
Any suggestion regarding the error not recognizing the files. I keep them
all in the same folder with the previous ones. the latest ones do not appear
in the folder where I put them when I use PowerPoint viewer to open
them.What could cause the malfunction?.
Thanks.

 

[JS]

Problem could be Office service pack 3 related.
Information about certain file types that are blocked after you install
Office 2003 Service Pack 3
http://support.microsoft.com/kb/938810

Also: http://news.office-watch.com/t/n.aspx?a=519

JS