Recent problems with erratic readings from my 3 year old Pool Pilot Digital DIG-220

My 15k gallon pool was completely rebuilt about 3 years ago in 2008, and we opted for a salt water generating system. The pool contractor installed a Pool Pilot Digital DIG-220 unit.
About a month or so ago in June 2011 the Pool Pilot display started showing erratic readings more often than had been the case. The strange behavior seemed to happen every few days.
A few days after I added a 40 lb bag of salt (usually needed at 2 to 4 week intervals) the red light would start flashing and the display would read "000 ppm" & "Add Salt 375 lbs."
So I would add another 40 lb bag of salt, but this pattern continued. I found that it was intermittent.
Sometimes it would stop (meaning it would return to no red light flashing and 3000-3600 ppm salt) after I jiggled the Tri-sensor connector, and sometimes it would stop after I cleaned the strainer basket (even though there was not much in it), but the erratic behavior continued.
Today I read a response from someone with a similar problem on the web page “http://www.poolforum.com/pf2/showthr...Contact-Issue”.
He had some luck with what sounded like a similar issue, and it was corrected by applying CRC "QD" Electrical Contact Cleaner.
I bought some at Ace Hardware on my way home from work, and applied it when I saw the red light flashing. I had just added another 40 lbs of salt 3 days ago because the Pool Pilot said it was needed, so I was pretty sure it did not need any more salt.
The CRC application seems to have worked for me, too.
The red light stopped flashing and the display went from "000 ppm" and "Add 375 lbs salt" to "3600 ppm".
Thank you, Pool Forum.