If any one can solve this unsolvable problem they are a genius

Hey
I am using Mac OS X Tiger and i have a problem. Someone seems to have hacked into my computer and deleted my old user name and setup a new username. i managed to get into the computer and delete the new username and setup another user name. I then put another drive into my mac and installed mac OS X Tiger on it and im now using that as my main hardisk. The old hardisk is in my computer as a secondary hard drive. The problem i have is all of my files which have great importance to me were on the other hard drive. Thankfully i know that they are still on the hard drive because the memory is still being used up. However there is still a problem. When i had the computer working before i got hacked i had file vault active. This meant that all my files were encrypted. This now proves aq problem because all the files which were only usable by my old user appear not to be on the hard drive despite the memory still being used up.

Is there any way that i can acces these files?

Thanks

Are you sure the data is still there.

Firstly select get info on that drive and select ignore ownership and permissions on that drive if you can

Secondly use MainMenu or Tinker tool to show invisible files in the finder

FileVault itself is an AES-128 encrypted disk image, and when it's enabled on a home folder, that home folder's contents are copied to the disk image and securely stored there;

Click to expand...

If you old home folder is on that disk it will be somewhere as a dmg disk image. If you can locate it copy it to your other hard disk first , then you should be able to mount the disk image using your original user name and password.

Here's Apple's page on how OS X handles deleted users. The disk image that louis mentioned may be found in /Users/Deleted Users.

Still nothing

Sorry it took so long to reply. All of my files are still there because when i go to get info it says all of the hard disk memory is still being used by it however there is no .dmg or .img file in the deleted users file.
Any other ideas.