Boot-up error

Hey guys. If you are looking for quite a brain teaser, here's one right here. I own a Sony PCV-RX540 running Windows XP Home SP2. Older Vaio model, purchased in December 2001. I'll cut to the chase here. It had a 60GB hard drive partitioned into 15GB (the first half, system boot drive) and 40GB (the second half). I bought a 160GB Maxtor drive at Office Depot about two weeks ago. The purpose was to put a clean install of Windows XP on the new Maxtor drive and use it as the primary and just have the other 60GB drive as storage. I used the system recovery disks and re-installed the OS from scratch. It worked fine. Two downsides though: 1) By default the disks are designed to partition the drive. 2) Partition process went wrong so I ended up with 7GB (system, boot), 120GB (space), 20GB (more space). After it was over, I got this idea to setup a multi-boot process: The Maxtor 160GB drive was the master running Windows XP and the 60GB slave drive ran Windows XP as well, just for the heck of it. At boot, I was able to choose which OS I wanted to use. I used the original OS on the 60GB to get the files off of my Maxtor drive with the intention of reformatting it into one huge drive and then copying the system files back. It worked perfectly. I can boot to both drives as before, but now there's a different situation.

I cannot boot directly to the Maxtor 160GB drive. I had to change the BIOS settings to use the slave 60GB as the boot drive and then put a refference in the boot.ini there to the 160GB boot drive. Doing so lets me boot to that other partition.

Something is preventing me from booting directly to my Maxtor 160GB drive. Ntldr and NTEDETECT.COM are both present and the boot.ini seems fine. I'm sure the answer is quite simple, and hopefully someone will be able to help me. Thanks in advance.