FCF model, WCinv previous, problems, several, capital, current

PieMan

FCF models are fairly straight fwd with exception of working capital piece. I've seen it calculated several ways and seems to be the one part of those problems that trip me up. Change in receivables + inventories - chgs payables.....or (current assets - cash) - current liabilities vs previous yr = working cap.

Any light shed on how to solve for this would be appreciated.