An informant to the former East German secret police held a management position at McDonald's for years. The man with Stasi ties is believed to have spied on a restaurant operator. Were managers at the fast-food chain looking for ways to terminate contracts with franchisees without having to pay them?

There's a hint of the smell of deep-frying fat in front of the McDonald's restaurants, even though such odors are not supposed to be detectable. "It's the filters," says Ulrich Enzinger, "it's time to change them again." The odor isn't very strong, but 49-year-old Enzinger has a keen sense of smell, honed by 18 years of experience at McDonald's.

One of his restaurants was in Lindau, a town on Lake Constance in southwestern Germany, in a prime location adjacent to the on-ramp for the autobahn to Munich. Unnerved, he gave up the business a year ago.

The restaurant is busy on this Monday morning, as Enzinger parks his car in one of the few empty spaces, locks the door and walks toward the entrance. Suddenly a dark sedan pulls up next to him, the passenger window opens and a voice says: "You are barred from the premises. Please leave."

The incident is reported to McDonald's German headquarters in Munich on the same day. More trouble with the franchisees - a common problem for executives at McDonald's Germany these days.