Opening balances and prior fiscal year

I am entering opening customer/vendor balances, some of theopen entries have posting dates that are 1,2 or 3 years before the current fiscal year. I have no problem with loading the balances but should I close the previous fiscal years once the balances have been entered?

Yes

You would need to close them anyway prior to doing the next real year end close as you cannot run this process with past years open. It is irrelevant anyway as presumably the debtors and creditors control accounts are balance sheet accounts. [:D]