Failed in last step of installation of Bootcamp 4.0 Windows 7

My MBP is the mid-2009 model with 2.53Ghz and 4GB RAM.

I later made an upgrade by taking out the Optical disc drive and inserted a SSD drive.

Then not long ago after Lion has been released, I installed Lion on my SSD while putting home folder in HDD.

When I was on Snow Leopard I installed Windows XP on my Bootcamp.

This time Apple dropped support for Windows XP and Vista, I guess I gonna give Win7 a go.

So I opened up Bootcamp Assistant to make a Windows partition, then started the installation.

It took me like 15-20 mins to let my system finish loading the required files on my Win7 DVD, after choosing the Windows 7 version (I chose Ultimate x64)

I formatted my Bootcamp partition to NTFS(required for installation) then clicked 'next'

Then the installation started, at first I thought it was successfully started but 2 seconds later I realised that I was wrong.

The installation was aborted, system said that required files are not found'.

After few tryings, I gave up and seeking for assistance.

I know the key is that my OS and storage system setup is not so common and maybe those who have the same setup like me facing the same problem, kindly help please 🙂
And also, is there any chance that my DVD has problems ?
I don't suspect that as other than that error it gave me it seemed perfectly fine.