Package: Kernel (?)
I was trying to install Debian 64bits in Virtual Box but it froze on selection of the first install option. After several minutes I tried "Expert Mode" only to see the message about 32/64 bits incompatibility as I was trying to install the 64 version on a 32 virtual machine. I suggest that would be nice if the installer checked this incompatibility before displaying the menu (much like Ubuntu does) with a error message.