We'd been having a client complain of "funky behavior" here and there for the last few months. He was a new client, so we didn't have a lot of background to go on, and couldn't tell how bad the problem really was, as it "seemed fine to us."
He signed up for our Support Agreement, and we installed the Watchman Monitoring Client. Two days later it reported a failed RAM chip.
We replaced the chip under warranty, and he's been happy since.