Time Machine Already Installed, problems with additional memory sticks.

I'm usually pretty good at figuring this stuff out on my own, but I got a little stuck here...

I've already installed DAX's Time Machine on the PSP and I have one 4GB Sandisk memory stick pro duo that works fine.

I bought another Sandisk 4GB memory stick pro duo and that stick won't boot up on the psp.

I think I need to put some files on that memory stick to get it to boot. I haven't done this since Feburary so I'm a bit rusty on all of this.

What do I need to do to get that second memory stick to work with the Time Machine?