I have tried to install FC3 twice now, its installs ok but after i shut down for awhile and try to reboot , it only goes as far as the hardware installation and stops? The last time I installed it I got the new Kernel updates and installed them, but when the system rebooted they weren't there, only the original SMP kernel. any help would be great, Thanks.

If your system is hanging at kudzu that might indiciate a problem with some hardware.

You could remove any extra hardware and see if you can boot successfully. You can also check your boot messages quickly via dmesg (run in a console or term) and see if anything stands out. Have you waited sufficiently long enough for any time outs (and then check dmesg)

I had some problems a while booting an nforce board... the install would go fine most of the time, but it would hang for various reasons. (Those issues have been resolved since then).

How did you get your new kernel updates? If yum properly finished an install it should have updated your /etc/grub.conf (bootloader configuration) to include the new kernel and automagically set the priority to boot the new kernel.