Pulleys are already fixed error in Belt mate

Hi everyone,

     am I the only one having problems with mechanical mates and belts working together? Put simply, i have a motor that turns a gear, that gear has a pulley which of corse turns a belt; that belt turns anothe pulley (duh), that pulley is attached to a screw system. Whenever i create the belt, i get an error saying that the pulleys are already fixed. Yet, when i turn the gear anyways, everything works as it should. The rebuild error is just annoying!

Thanks for your suggestions

SolidworksAssemblies