Of course, being a Slackware user for the past 5 years, I know that if it doesn't work ir must be because I did something wrong :-D
It was the first time I did a full install, before I always installed choosing package by package ('expert' installation) and never had a problem. IIRC, if you choose only a generic kernel to be installed the MKINITRD step will be included in the setup process. What I'm calling a "quirk" is the fact that this step will be skipped if you choose to install a huge kernel.
I'm a LinuxQuestions user, so I know the forums and I always look there for help