external drive was corrupt...lost 4 sessions after copying them to drive. help!

[djc8902]

I just got a western digital 80 gig drive to store my audio on and copied 4 sessions i had on my internal hard disk/desktop onto the drive...restarted and opened them with no problem and then moved the sessions from the desktop to the trash and emptied trash. moments later, the new firewire drive freaked! I lost 2 of the 4 sessions and on one of the other two sessions i lost vocal tracks. Is there a way I can restore the sessions from my internal hard disk after deleting them from the trash?!!! Please someone help quick, client is coming to mix tomorrow! aaaahhhhhh.