enable inputs on l297 / 298

I have another problem with my l297/298 controller.
When I turn on the controller with the enable input high, the
output current goes sky high (or would if my temporariry bench power
supply did not have a current limiter)
I have to ensure the enable is kept low untill after the power is
turned on. The l298 data sheets does mention that its enable inputs
have to be kept low on power on.
Funnily enough I had no problem with this when I supplied both 5v
and 30v from the same dual supply and not as I do now w-with the 5v
derived from the 30v via an on board regulator.
I'm thinking that an RC network will produce an automatic delay in
raising the enable from low to high on powering up but like to check
if anyone else has had, and solved this problem first.

thanks in advance

Alan