Thanks for posting this - you reminded me of a plea for help from my (new) girlfriend which I had completely forgotten about.
She was after a copy of Office XP so she could work at home on her laptop. I sourced a copy of Office 2007 for her, stuck in on her machine, and assumed all would be well. In a stunning show of post-sales support (or rather lack of), I just assumed her inability to open files at work created at home with word 2007 was some kind of 'user error'.
I have now emailed her the various bits of info listed above, and will undoubtedly earn myself some brownie points!