there are a few things you might try:

Restoration by Brian Kato Does not need installation so it doesn't overwrite anything. The ONLY downside is that after locating all the deleted files you have to recover them one at a time. Time consuming but I haven't seen it fail
http://www.win-freeware.com/REST2514.htm

PC Inspector File Recovery FREEWARE
http://www.pcinspector.de/default.htm?language=1

Digital Photo Recovery v2.0.3 ($29.00)
http://www.photosrecovery.com/

Lots of utilities and prices vary
http://www.ultimateslr.com/memory-card-recovery.php

FREE TRIAL
http://www.filerecoverytools.com/products/fr_sd/