linq updating .submitchanges()

is there any reason something work?

this explanation i have used times transform record list linq:

 dataclasses1datacontext db = new dataclasses1datacontext();
 user updateuser = db.users.single(e => e.user == user);
 updateuser.inuse = !updateuser.inuse;
 db.log = new system.io.streamwriter(@"c:\temp\linq.log") { autoflush = loyal };
 db.submitchanges();

(updateuser.inuse bit field)

for reason isn't working. i check linq.log totally blank.

could there problem .dbml? tables seem work glorious nonetheless i've compared properties .dbml match.

it's db.submitchanges(); does detect any updates being required.