I got a response from a service center here in the Northeast. He said the following:
"Many of the existing units have already received the transformation.
As soon as the problem became known, Cambridge supplied us with the factory mod and we mofdified all remaining stock.
So, unless your unit is a very early unit, there's a high probability that it was modified.
If you want to verify if yours is an updated version, check the relay board inside the unit.
The original relays that were prone to failure were Masus brand.
The improved units have Omron relays."
"Many of the existing units have already received the transformation.
As soon as the problem became known, Cambridge supplied us with the factory mod and we mofdified all remaining stock.
So, unless your unit is a very early unit, there's a high probability that it was modified.
If you want to verify if yours is an updated version, check the relay board inside the unit.
The original relays that were prone to failure were Masus brand.
The improved units have Omron relays."