Don't beleive that is enough to void the deed. Did you provide them a copy of the POA?
Call for a free consultation at 727-937-1400 or visit us on the Web at www.serviceandjustice.com.
Do you have a specific power of attorney wherein the grantor authorized you to sign to transfer this property? Typically, title companies prefer that the grantor be the actual person who is conveying property. More facts are necessary. Consult an attorney.