First note that you have two partitions on the same disk. An MBR (protective) and GPT. You have enabled the boot flag on your boot partition in GPT but not MBR. This is very confusing, I realize, but 'boot' for MBR is not the same thing as GPT at all. Because of the 'boot' flag in GPT, in reality your GPT is claiming your linux boot partition is actually an EFI System Partition, because that's what the parted 'boot' flag does on GPT disks. Here is what I would do:
1. Use fdisk to set sda1's boot (active) flag to be enabled. And see if your problem is now fixed.
2. Whether it's fixed or not, the next thing I would do is use parted to toggle the boot flag on sda2 (i.e. remove it). This will set the partition type from EFI System Partition back to Windows Basic Data, which is (unfortunately) the partition type GUID commonly used for linux. Alternatively you could yum install gdisk and use it to change the partition 2 type code to 8300 which is for linux file system - this is what I've done.
I keep forgetting about the nogpt kernel parameter. That's the easiest work around for this problem. So when you go to install from the DVD, hit tab to edit the boot line and add nogpt to the end and then continue booting off the DVD. Then reinstall wiping out the whole disk.