Yes, its very likely that your problems partly come from the fact that AMD processors are not actively supported by MIR. As you mentioned yourself, this is also explained in the system requirements ( -> [URL]http://vsl.co.at/en/211/497/1687/455/1666/1328.htm[/URL]).
Still it takes me wonder that you see crashes while saving, as this shouldn't be part of the issue - in fact we know about a few users that use AMD-equipped machines for MIR, without basic problems like the ones you describe.
Do you see any kind of error messages? If so, please just press Ctrl-C when the message window is on top, paste it and send us the text.
Kind regards,
/Dietz - Vienna Symphonic Library