Why can some users receive and others not, when the Purchasing period is in "future" status?

At the beginning of the month, the Inventory periods were opened for every inventory organization.  The GL and Purchasing periods were in "future" status.   Some users could receive parts while other users got an error about the period not being open.

What makes the difference between the users?  Ideally, we would like the new Purchasing period to be in "future" status until the prior period is closed, so we don't have two periods open at once.  But we don't see the difference between the people who can transact and those who cannot.   Please help!

Regards,

J