have you tried turning off selinux?have you tried booting into RH by setting your /boot->hda1 as active boot partition?
If you can boot into both oses by without bootloader, by setting the boot flag (in)active there must be some misconfig in bootloader, if you cant boot into RH by boot flag method think what may have gone wrong while in bathroom! -- http://mm.ilug-bom.org.in/mailman/listinfo/linuxers
