If the disc image cannot be found then I suspect it's been overwritten already. Even though you haven't saved a file, the OS is writing to the drive all the time. You might try one of the other tools. Sometimes different tools produce different results.
Recovery software won't find the individual files on the disc image. The only file involved is the disc image.
I know this doesn't help, but for the future you should institute a backup strategy. The loss of your files would have been prevented had you a backup. See the following;
Basic Backup
Get an external Firewire drive at least equal in size to the internal hard drive and make (and maintain) a bootable clone/backup. You can make a bootable clone using the Restore option of Disk Utility. You can also make and maintain clones with good backup software. My personal recommendations are (order is not significant):
1.
Retrospect Desktop (Commercial - not yet universal binary)
2.
Synchronize! Pro X (Commercial)
3.
Synk (Backup, Standard, or Pro)
4.
Deja Vu (Shareware)
5.
Carbon Copy Cloner (Donationware)
6.
SuperDuper! (Commercial)
7.
Intego Personal Backup (Commercial)
8.
Data Backup (Commercial)
9.
SilverKeeper 2.0 (Freeware)
10.
MimMac (Commercial)
11.
Tri-Backup (Commercial)
12.
Time Drawer (Commercial - similar to Time Machine)
The following utilities can also be used for backup, but cannot create bootable clones:
1. Backup (requires a
.Mac account with Apple both to get the software and to use it.)
2.
Toast
3.
Impression
4.
arRSync
Apple's Backup is a full backup tool capable of also backing up across multiple media such as CD/DVD. However, it cannot create bootable backups. It is primarily an "archiving" utility.
Impression and Toast are disk image based backups, only. Particularly useful if you need to backup to CD/DVD across multiple media.
Visit
The XLab FAQs and read the FAQ on backup and restore. Also read
How to Back Up and Restore Your Files.
Although you can buy a complete FireWire drive system, you can also put one together if you are so inclined. It's relatively easy and only requires a Phillips head screwdriver (typically.) You can purchase hard drives separately. This gives you an opportunity to shop for the best prices on a hard drive of your choice. Reliable brands include Seagate, Hitachi, Western Digital, Toshiba, and Fujitsu. You can find reviews and benchmarks on many drives at
Storage Review.
Enclosures for FireWire and USB are readily available. You can find only FireWire enclosures, only USB enclosures, and enclosures that feature multiple ports. I would stress getting enclosures that use the Oxford chipsets (911, 921, 922, for example.) You can find enclosures at places such as;
Cool Drives
OWC
WiebeTech
Firewire Direct
California Drives
NewEgg
All you need do is remove a case cover, mount the hard drive in the enclosure and connect the cables, then re-attach the case cover. Usually the only tool required is a small or medium Phillips screwdriver.