MS Office "Compatibility Pack" can't read/write spreadsheets (orpresentations) in MS XML format

FYI, there appear to be problems with MS' Compatibility Pack.

Microsoft has been telling folks that they can read/write
Microsoft's XML format from older versions of MS Office by
installing a "Compatibility Pack".   However, as reported here:
http://news.office-watch.com/t/n.aspx?a=85
It turns out that the Compatibility Pack only works with Word XML format,
and _NOT_ Excel spreadsheets or Powerpoint presentations.
The article says that Microsoft is trying to correct this.

I thought several people here would want to know this.

--- David A. Wheeler