ODF's created in Office will only render properly under 2007. And Office will only render properly ODF's created under Office. EVERY OTHER OFFICE PROGRAM THAT USES ODF WILL WORK W
M$ intentionally blew it. What's that? What proof do I have? A spreadsheet created under ODF on, say, OpenOffice, can have in a cell TODAY(). This command tells the rendering program to read the current date from the system clock and put it in this cell as soon as it opens. You can't get more direct than that. You couldn't get this wrong unless you tried. Office will put the date you create or open the document in the cell, then erase the TODAY() command. It will also alter formulas in other cells if you created the spreadsheet under another office program.
So my suspicion was correct -- just like their C++ compiler, M$ is intentionally fudging standards just to seem compliant while actually not being it.