Permissions issue on NAS when accessed by Mac Yosemite

Hello Mac community.

Hopefully someone can provide a "simple" answer to my dilemma.

I have a windows based network where I've installed a Seagate NAS device. All works well and all can connect.

The issue is from the attached Mac Yosemite system. If the Mac updates or creates a file in the Public section of the NAS then no one else can access that file as they receive the error "insufficient permissions".

The NAS configuration treats the Public fold as just that (unrestricted). I've noticed on the Mac that it shows the permissions as r+w by the owner and no access by everyone.

I'm hoping that there is a setting for this as it is causing havoc with production.

Thank you in advance for any suggestions.