Acer 7745g - HDD Caddy

Hello All!

I got an Acer 774 Notebook, which has 2 HDD Slots. But since Acers Plastic would cost ~60EUR, I want to use a HDD Caddy inside the DVD Drive.

I Bought a Caddy, placed the HDD inside aaaaand - Freeze. Just right after the BIOS Post.

Here are the Configs I tried:

1. Without Caddy and DVD -> BOOT
2. Caddy inside, no HDD in Caddy -> BOOT
3. Caddy inside, with HDD -> NO BOOT
4. Caddy inside, with HDD, SATA Port disabled -> BOOT

So the Problem is that the BIOS tries to init(?) something @the ATAPI or something..
The Drive inside the Caddy is shown in the Bios, with correct Serial and co.

It just freezes after the Post. I read this Post, but since there was no Solution I open this one.
I use a flashed BIOS from here which enabled the "Intel" Tab - I tried multible Options, but nothing works.

I hope someone could help me!

Regards