Lytebox Not Working on Forwarded/Masked URL

Ok, so please bear with me; my knowledge of all the gears and cranks behind displaying webpages is very limited, but I'll try to make this as clear as possible from what I know.

I created a website in Photoshop, sliced it up and used iWeb to generate the HTML code for me. I published the site to a folder, and then proceeded to edit the HTML so that I could incorporate Lytebox, via these instructions. Once everything was done I uploaded the folder to the Web -->Sites folder on MobileMe's iDisk. Now, when I browse to my MobileMe-hosted webpage everything works fantastically and I'm happy.

Then I used GoDaddy to forward my personal domain URL to the web.me.com one, and mask it. It worked just fine, EXCEPT that Lytebox no longer works. Images that I click on just open in new tabs, rather than a lightbox-style frame within the current window.

For some reason that I can't figure out, Lytebox will work when I navigate to the site through web.me.com/noahchristman, but not when I navigate to the site through www.design-planner.com, which is just URL that forwards and masks the former one.

I'd really appreciate your help, since I'm at a loss as to what I can do to fix it. Thanks!

EDIT: So I turned off the masking of my personal domain and it appears that was the cause of Lytebox not working correctly. So the new question is this: anybody know how I can get masking to work so that the long (web.me.xxxxxxxx) URL isn't displayed? Or alternatively, what the cause of Lytebox not working when URL masked is, and how to rectify it in the HTML code?

Again, thanks a lot for any help!