Problem with triple boot/gptsync/hybrid mbr

[les02jen17]

Using this well written guide by RehabMan of tonymacx86, I was able to triple boot Windows 8.1, Mac OS X Mavericks and Ubuntu 13.10. Well, almost. The problem is with the Ubuntu installation. So after creating the initial partitions which are FAT--for Windows (which will be changed later to NTFS), exFAT--for storing files across all the operating systems, HFS+ for Mac OS X, then FAT--for Ubuntu (which will be deleted later and sliced for swap area and ext4 respectively, for Ubuntu) using Disk Utility from my Mavericks USB, I proceeded into booting into the Ubuntu live usb. First thing I do is run Gparted, to format the FAT to NTFS (for Windows) and then delete the other FAT and create 1: 8GB swap partition and 2: ext4 partition. Now here's where I'm having problems. I then installed and ran gptsync so that it will sync and update the hybrid mbr. The issue here is that gptsync does not seem to be able to do it. It detects the ext4 partition as "unknown" and thus saying that it will not be able to continue. However if I delete that partition, it would be able to write it. So I did temporarily deleted it, until I figure out how I can fix it, and that's the reason why I was able to continue installing Windows and Mavericks. They both boot just fine using Chimera. Does anyone know of an alternative tool that can sync hybrid mbr like gptsync that can detect and work with ext4 file systems? Thanks in advance.