ftp://beta.altlinux.org/p6/simply/altlinux-6.0.1_rc4-simply-i586-ru-install-dvd5.iso , ftp://beta.altlinux.org/p6/simply/altlinux-6.0.1_rc3-simply-i586-ru-install-dvd5.iso for a reason unknown to me doesn't boot on an old Toshiba portege laptop... although the older DVD with 6.0.1RC2 (of 2011/10/20) does boot. ftp://beta.altlinux.org/p6/simply/altlinux-6.0.1_rc4-simply-i586-ru-live-cd.iso also does boot on this computer. It tries to read the DVD, and nothing appears on the black screen. Then the computer proceeds to other boot methods. I'm not sure: perhaps, it's not an RC4 vs RC2 problem, but the reason is that the RC2 is recorded onto a DVD+R whereas I have recorded the RC4 and RC3 images onto DVD-Rs. I shall test this.
Images are builded with different tools nowaday. hopefully the issue is not exist now.