This set of results is kind of curious, actually... well, I would have said the issue is purely that the Mac Firefox is not pushing out formatted text to the copy buffer. But the fact that Windows Firefox (which apparently is) is not able to paste rich data into Mac Word is a standout (you can paste rich text between, say, Windows Word and Mac Word, with Parallels or whatever you're using, right?). So my guess would be that, while the Windows version of Firefox does generate rich text in the copy buffer, it does it with a more obscure format type that Windows apps such as Office for Windows understand, but not in a format that Macs understand. Which is troubling -- why would Mozilla have chosen a weird format for their copies?