ToyotaMan - I have a 2006 Corolla S with 8,000 miles and mine does the same thing...
But I LOVE IT that it does that! I used to love that about my '90 Honda Prelude, and missed that when I went over to the dark side and got an Oldsmobile Intrigue...
Reason being: I live in Pittsburgh where there are tons of hills on the highways...that automatic slowing down allows me to not have to ride my brakes when I come down a hill or am tailgating someone going up a hill...my GM car used to INCREASE SPEED going down a hill heading into the Fort Pitt Tunnel and I went through 2 sets of brakes & rotors in 30-40,000 miles
If I want to slow down a little bit, I can take my foot off the gas with this car...but when I used to do that with my GM car, it maintained the same damn speed and coasted at that rate or faster...I hated that!
P.S. My Toyota Sienna does the same thing as the Corolla
P.P.S. ToyotaMan...I noticed that you live in Cumming, GA...I go there at least one a month since one of our factories is located in town there (hint: It's a food manufacturer)! SMALL WORLD eh