[Dellaster]

I just did a first-time install of Calibre 6.46 on Ubuntu 9.10 64-bit with no problems, for what it's worth. That is, no problem except that this Linux version lacks a DR800 profile.

Edit: Oh, and the Windows 7 64-bit upgrade was done earlier today, also with no problems. Installed over the top of the old one, no uninstallation, as per usual.