AIS Base Stations Moving !

[Ptizef]

Does anybody has experienced the same behavior ?
Base stations moving and creating very odd tracks (see screen dumps attached)
This was experienced with 3xx version this summer along north Spanish cost where many of them were installed
The devices are net book XP and AIS "Ais engine 3" from Nasa Marine.
I never hag this problem with other Ais type since 3 years I used it with the same devices and Opencpn all versions
Jean Pierre