I have a (work) PC that long ago was running Office 2003 and I put OneNote 2007 beta on it.
That was the end of Datasheet View and upload multiple files. So I quickly learned that if I wanted to use either I had to go back to my by now over six years old reserve office PC (where there have only ever been Office 2003 applications installed).
About six months ago my work machine was so sc***d up that it was necessary to put a new image on it. That image included the (work standard) Office *2003* (unbelieveable but true) which I then upgraded to Office 2007 myself.
I kept on assuming that Datasheet View and upload multiple files wouldn't work.
However yesterday there was a message in a forum about someone's upload mutiple files not showing PDF files, so without thinking I checked it on my work machine today. Yes, I could see PDF files OK.
But hang on, upload multiple files shouldn't work on this machine .... So I tried Edit in Datasheet View and that worked too.
Motto: Even if these once don't work, check them now and again as something you have done in the meantime might get rid of the remnants of that mixed (Office 2003 level / Office 2007 level) environment that was causing these things to fail.