are you certain the power loss is in the GAL device and not the associated circuitry? if it is jut the GAL there is not much you can do. the device has its own internal impedance which you have no control over. you could try reading the datasheet and see what the minimum current required is. then place a resistor at the input to ensure this current.?
also check that all un used pins are tied to ground through a large resistor, and calculate the maximum possible resistor as any pull-ups.
Hi,
If power is a real issue, you can use a zero power or low power version GAL, or switching to a Zero Power CPLD. Lattice has now ultra low power (10µA) standby CPLD.