fritzbox 7390 as cordless phone base station

I use my fritzbox 7390 modem router as a cordless base staion for my panasonic dect phones, it works fine, except once a week usually in the middle of the night, the cordless phones ring twice, if you answer no one there, or if you leave it it only rings the twice.only once a week but at 2am which is when it usually happens anoying. Anyone else with 7390 got this problem, or any ideas how to stop it.

Hi I have Fritz!Fons and a Gigaset DECT phone connected to my 7390. Phantom calls are a known problem with this router (and some other makes as well). We get a call about once a week at random times. We have disabled night calls on our bedroom phone so that we don not get disturbed. It has been reported to AVM and to date they have not come up with a solution.