protected oma to mp3

I have a Sony HI MD minidisk recorder mzm-200 and I have previously, over 1.5 yrs ago, uploaded some of my personal field recordings and backed them up to hard drive. (cultural preservation for Tibet)
Some of these recordings are still in the oma format, having been uploaded with Sonic Stage v. 4.3 and saved to my back-up hard drive several months ago.
(OS Vista Ultimate 64 bit sp2.)
My computer crashed recently and I was unable to back up my Sonic Stage library. After this I tried to re-import the precious field recordings I made myself in Tibet after a reformat and fresh install of windows vista sp2 and sonic stage. (The files had been copied to another drive for back up, not backed up through the program.) Apprarantly Sonic Stage v.4.3 attached DRM rights to my self made recordings, recorded by me with a mic!

Even though these files were originally uploaded/transfered from my MZM_200 into Sonic Stage and saved onto my hard drive, now Sonic Stage will neither import back to its program my previously uploaded oma files saved onto my external hard drive

When i try to re-import the old ones previously transfered, then I cannot open the recordings because I get an error message about a copyright problem from Sonic stage program saying I don't have the rights. This error message makes me completely unable to use my precious field recordings.

I desparately need a way to remove the DRM wrapper imposed on my oma sound files and be able to convert them to MP3?

Please help I am desparate.