I think
TestDisk could be what you are looking for. Be sure to read the manual before attempting a recovery and use at your own risk..
It has worked for me in the past and saved me a lot of trouble. I had been using Partition Magic back then too, I would suggest switching to another partitioning program, it seems Partition Magic can be quite buggy sometimes.
Have you tried googling for the error that comes up? You might want to try that first..