In Virginia, you can get a default judgment set aside if there was fraud on the court, the judgment was void, with proof of an accord & satisfaction, or you were a member of the military when you were allegedly served. http://lis.virginia.gov/cgi-bin/legp604.exe?000+cod+8.01-428
A lack of proper notice could make the judgment void, or it could have potentially involved fraud on the court by the Plaintiff. You would need to file a motion with the court to set aside the judgment. I suggest you consult a local attorney to assist you in this matter.