Boot problem

[flyingdog]

I have an issue trying to boot, I've tried everything, several different solutions: chain0, grub, native.... OSX installed on a system with 4 partitions does not boot. BUT it boot using the installation cd without hitting enter ad the first darwin loader. It seems an installation problem, like a boot sector was not installed on the partition. Activating the Mac OS partition does't work as well. Using Advanced Fdisk boot manager.. nothing.. every other system, I have a win xp and a fc6 works well. I ve tried to install it on another laptop, same hw.. nothing ... the partition is correctly set to type=af .. really I don't have a explanation. I used Jas 10.4.8 to install it and I ve added the jas pathced kernel for intel during the installation. I am starting to thing that the installer didn't installer a boot loader into this partition. Is there any way to do it manually? ... just to repeat, booting from the CD it recognize the partition and start from the hd working perfectly.... THANKS for every help or suggestion.