The INSERT statement conflicted with the FOREIGN KEY constraint

Here's my code behind:
protected void cuwRegister_CreatedUser(object sender, EventArgs e) { //create new create user wizard to grab the user name and password CreateUserWizard cuwNewUser = sender as CreateUserWizard; // Insert a new record into UserProfiles foundBoardDataContext addBrdMemberDC = new foundBoardDataContext(); foundBoard newMember = new foundBoard(); TextBox txtFirstName = (TextBox)cuwNewUser.CreateUserStep.ContentTemplateContainer.FindControl("txtFstName"); TextBox txtLastName = (TextBox)cuwNewUser.CreateUserStep.ContentTemplateContainer.FindControl("txtLstName"); newMember.brdFstName = txtFirstName.Text; newMember.brdLstName = txtLastName.Text; newMember.userName = cuwNewUser.UserName; newMember.password = cuwNewUser.Password; newMember.emailAddr = cuwNewUser.Email; addBrdMemberDC.foundBoards.InsertOnSubmit ...