I am also having same problem and unable to open "Sub accounts" under ACCOUNT NUMBER 6210 WAGES AND SALARIES.
at new account creating form: combo-box of Default linked account for is not showing header account ACCOUNT NUMBER 6210 WAGES AND SALARIES.
I am related with a travel agency and our income and sale is on commission base and also we pay commission to our sub agents, So it also very difficult to keep a commission records in NCH express account.
So may I have any help in this regarding?