There used to be something about not getting the "pay advance" on the 1st of the month if your credit was below a certain threshold. You still get paid for the full credit, but it comes in one check, on the 15th of the month following. Not sure if that is still in effect or it it matters to you that there wouldn't be a paycheck on the first of the month.

Honestly, I'm surprised you were allowed to drop below 50 .. they must be fat on manpower in your fleet /seat.