Yesterday I've upgraded a Mint 8 32bit to a Mint 9 RC 64bit version. I followed the tutorial performing a fresh installation. Before I installed the new RC I made a backup of the data and the software selection.
Anything went fine until I restored the software selection, what left me with a system without mintmenu, without all the taskbar apps and with a big bunch of apps that do not start at all (eg. Firefox, Google Earth, Open Office ...).
Perhaps it's my fault since I made a cross upgrade 32->64 bit. But it's nowhere mentioned in the tut that there are issues making a cross upgrade this way. I thought Mint would recognize its version and would grab the appropriate software from the repos: the actual version of the softs and the matching bit-width. My guess: this is the problem. In this case the tutorial should include a warning.
But maybe I'm wrong and something else caused the trouble, since it was my 2nd and "test"-installation of Mint 8 and perhaps somewhat ill-configured (so no harm at this point). Anyway, tonight I will install Mint 9 RC 64bit again restoring my data but without restoring my software selection.
Alas, did I already mention my deep appreciation of Clem's and the team's work ... ? Thank you all!