There are a number of standard system Line Types which you cannot update or delete (these are the records with an id of 22 or lower). Please look at the table below if you are trying to make your own variant.  
  Object: 333. Click here for more information.  
  DataReturn Text A comma delimited list of advanced search fields to be returned after a successful save
  Id Numeric  
  Remove Numeric Pass '1' to remove the item
  IncludeInAllowancesNonTaxable Text (1) Y / N [default]
  IncludeInAllowancesTaxable Text (1) Y / N [default]
  IncludeInDeductions Text (1) Y / N [default]
  IncludeInGrossSalary Text (1) Y / N [default]
  IncludeInLeave Text (1) Y / N [default]
  IncludeInLeaveLoading Text (1) Y / N [default]
  IncludeInLeaveType Numeric 1 = Annual [default], 2 = Sick, 3 = Long Service, 4 = Leave Without Pay
  IncludeInPostTaxSuper Text (1) Y / N [default]
  IncludeInSalarySacrificeSuper Text (1) Y / N [default]
  IncludeInStandardHours Text (1) Y / N [default]
  IncludeInSuper Text (1) Y / N [default]
  IncludeInTaxAdjustments Text (1) Y / N [default]
  Notes Text (2000)  
  Title Text (50) Mandatory
  Include In Allowances NonTaxable Include In Allowances Taxable Include In Deductions Include In GrossSalary Include In Leave Include In LeaveLoading Include In Post Tax Super Include In Salary Sacrifice Super Include In Standard Hours Include In Super Include In Tax Adjustments
Additional Employee Superannuation             Y     Y  
Administration       Y         Y Y  
Allowance   Y               Y  
Annual Leave       Y Y       Y Y  
Bonus       Y           Y  
Commission       Y           Y  
Deduction     Y                
Leave Loading       Y   Y       Y  
Leave Without Pay       Y           Y  
Long Service Leave       Y Y       Y Y  
Normal       Y         Y Y  
Overtime (Superannuation Exempt)       Y              
Paid Parental Leave (Superannuation Exempt)       Y              
Public Holiday       Y         Y Y  
Rostered Day Off / Time in Lieu       Y         Y Y  
Salary Sacrifice Superannuation               Y      
Sick Leave       Y Y       Y Y  
Split Shift Allowance   Y               Y  
Supervisor Allowance   Y               Y  
Tax Adjustment                     Y
Termination - Unused Annual Leave       Y Y            
Termination - Unused Long Service Leave       Y Y            
Worker's Compensation       Y         Y Y