Mess up with FileVault and Short Name

Hi everybody!

I have made some mess here in my MacBook Pro with MAC OS X 10.5.6 and I really need somebody help. I really don't have nobody else to ask that.

First of all, I have turn on the FileVault of my Adm Account, then I try to change my short name just using the advance panel of adm user. Then when I restart my MAC I can't loging because are showing some error with my new short name.

Now the access to my MAC is totaly blocked and I just have access to single-user mode (starting with Command + S pressed) and the terminal.

I have tried change the directory name but it is just read-only directory. I have tried to get access using security mode but this do not helps. I have tried to use the master password but this do not helps at all.

I am "newbe" using the MAC terminal so, PLEASE, can anybody help me to fix this mess up? IŽd like to come back the old short name and get again the acces to my MAC.

Thank you very much for your all attention.

Best regards,

Fabio Rueda
fabio.rueda@hotmail.com