If partitions are dirty, and we ask the installer not to format the partitions, it will reboot in order for us to fsck the partition. Anadonda should really do that itself.
One problem is that if we fsck and then need user input, that is ... nearly impossible to do without a terminal. I'll consider for the future at least for the case where the partition comes out fine, but if user input is needed, then I'm not sure what I'll be able to do.