I have never seen it take more than a couple of minutes to boot up. I know KDE checks for a minimum of 81mb ram or ram + swap. If not enough memory is available it's suppposed to default to use twm, a very basic window manager.
Icewm is pretty ncie, its minimal and sort of setup like windows. Fluxbox is also pretty neat since you can access your menus just by clicking the desktop. XFCE is sort of in between icewm and KDE in its level of complexity and features. In knoppix, there's also windowmaker but I've never used it. So that's 6 window managers in all to choose from, and the default is the most resource hungry. I'd try out Icewm, fluxbox, or xfce to see if the long boot-time goes away.
It's also possibkle the hardware detection is having trouble with the video card/monitor and has to retry several drivers before finding one that works. In which case there are some cheatcodes for framebuffer mode, for an alternate xserver, and to select certain video drivers, which could help once we can identify what the trouble is.
