Users of one of suburbia's most basic conveniences -- the garage door opener -- are locked in an odd situation with the U.S. Marine Corps.

A strong radio signal coming from the Quantico Marine base in Prince William County is neutralizing perhaps hundreds of the remote controls that move the garage doors up and down.

The Marines are using a frequency that is also used by some remote controls. The powerful signal shuts down any remote in its bandwidth, no matter who is holding it -- mothers with screaming children trying to get groceries in the house or gridlocked motorists looking for a light at the end of their commute. Nothing can be done but get a new system operating on a non-conflicting frequency.

Queen Carroll of Dale City, a widow in her early 70s, shelled out a few hundred bucks to get a new receiver and remote. She'd like to send the bill to the Marines. Before the new system was installed, the only way she could open and close her garage door was by using a switch on the wall of the garage. That is a pain at any age, particularly in the winter.

"I feel there should be some kind of compensation," Carroll said. "I am a struggling widow, if you will, and I praise the Lord I'm still here, but I am on a budget. When things like this come up totally unexpected, it is very upsetting."

Repair shops started getting a flurry of calls as soon as the Marines began using the frequency in late December.

"I'd say that first week, just out of Prince William County, I would guess we got about 15 calls, and then since that time about 25 more calls," said Jerry Bahorich, manager of Affordable Garage Door in Stafford County. "And we're just one company. There are 15 other companies that do business in Prince William County."

Rob Roberts, sales manager at Cristar Garage Door & Controls Inc., in Sterling, estimated that hundreds of people have had their remotes neutralized.

"It is a big thing within the industry," he said. "They are taking their frequency back. It isn't just around Quantico; it is everywhere, anywhere there is any type of military installation."

Suburban residents who have experienced a disruption in their point-and-click lifestyles can blame it on national security, according to a spokesman for Quantico.

"Marine Corps Base Quantico transitioned to a new bandwidth for land mobile radios in 2005 as part of a government-mandated, Department of Defense-wide conversion to narrow-band systems from wide-band systems in military bases around the country," Lt. Brian P. Donnelly said. "The transition was made to foster more efficient spectrum use, allowing a variety of military and government organizations to better protect national security."

Garage door freeze has broken out in other areas near military installations. Just before Christmas, hundreds of people around an Air Force facility in Colorado Springs reported that their remotes died when the 21st Space Wing began testing a frequency that would be used for homeland security emergencies or threats. Two years ago, testing of the system generated a dozen calls to Fort Detrick in Maryland.

Since the years preceding World War II, the military has held a portion of the radio spectrum in reserve, from 138 to 450 megahertz. That part was borrowed by remote control manufacturers with the understanding that the signal be weak enough to be overridden by the military.

The reserve frequencies became active after the Sept. 11, 2001, attacks, when officials discovered that first responders could not communicate with one another because they were operating radios on different frequencies. The Defense Department is using the mothballed frequencies in a system that eventually will link military and civilian emergency responders.

The system has been slowly put into place at military installations across the country.

Carroll, who has lived in the same house for 28 years, less than 10 miles from the base, understands very well the needs of the military. She worked at Quantico for years, and her husband, Eddie, who died three years ago, spent 29 years in Army intelligence. "I'm always pro-government," she said. "But I feel very strongly that if this is something that is happening to seniors in the area, it may seem like a small amount of money to the government, but it is a lot to me."

There seems to be no pattern as to whose garage doors are blocked. Carroll does not know of any other people in her neighborhood who have had problems. Garage door manufacturers have said that an estimated 50 million remotes could be affected.

For Carroll, getting out of her car to open and close the garage door was not only an inconvenience but also a matter of security if she was coming home at night. She also heard a rumor that the military radio signal has played havoc with garage doors, opening and closing them at all hours of the day and night. It didn't happen to her door, but she has heard about it from other seniors who told her it has tormented others. There is even talk on suburban streets that the military signal can pop open car trunks, which isn't true.

"People in surrounding areas might experience interference with their wireless garage door openers," Donnelly said, "but should not experience unwanted garage door movement. They might not be able to use their remote controls, but their garage doors should not move up or down on their own."

Robert Paulus, service manager at Automatic Overhead Door Co. in Fredericksburg, which serves all of Northern Virginia, said that at the end of December, "everyone's range went out of whack." He said the company went out on more than 30 service calls. When some customers learned that the Marines might be to blame, they thought about trying to get some money out of Quantico's treasury. "I ran into a few of those, and I just told them, 'I wish you could do that, but good luck trying.' " The customers threw up their hands and opened their checkbooks.

In this case, the Marines own the airwaves.

"Consumer wireless devices, such as garage door openers, operate on an unlicensed basis, meaning they are required to accept any interference from licensed spectrum users, including the Department of Defense," Donnelly said.