Roger,
The 7091 is being used to control an eight month old 6000. The pump was cleaned about five weeks ago. I don't see any corrosion on the connector plugs.
I may also have a related or unrelated issue with my photo sensor. I'm having to place it directly under my halides before it will allow the 7091 to exit "night" mode. It use to operate correctly at locations somewhat distant from the direct light.
Even with the photo sensor unplugged, the 7091 still produces a significant discrepancy in the pump timings.
Thanks.