Cycle Stop - stopped working?

I have a CSV1 60lb Cycle Stop valve installed in the drop pipe of my 40 foot shallow well with a 1 hp, 18 gpm submersible. It worked fine for six months or so and then I noticed it gradually required greater flow (above the preset 1 GPM) to keep the pump from cycling. It is now to the point where even when my open loop geothermal unit is calling for a continuous 7 GPM, the pump will cycle - on for seven or eight minutes, off for about two as the tank drains.
Do these things wear out? Do I need to pull the pump and clean it maybe? I am kind of at a loss here as it has only been installed for a a year or so now. Any thoughts would be greatly appreciated.

Your going to have to pull it up to see. It could have something in it that holds it open, like a spring from a broken check valve. It could be that it doesn't have the CSC1 coupling that is needed to hold the pumps weight when it is installed in the well, and the valve is pulling apart. Call the company at 800-652-0207 and get some help if you need it.

Had to reply with an update to this thread.
Called Cycle Stop and received EXCELLENT customer service. Not only were they helpful on the phone with a couple things to try, but they sent out a free replacement valve even though I didn't purchase the original directly from them.
The likely problem was IRB coupled with an incorrect installation by a well driller - who I really didn't want back as they seemed as though they didn't quite know what they were doing when they were out for the original install.
I now have a functioning Cycle Stop - installed correctly - and a new appreciation for companies that provide quality customer service.