If two users go to the "Print Checks and Forms" screen, they both will have the same check number shown as the first check number to use. This causes a duplicate number to be used for two different check prints. Is there a way to prevent a duplicate check number when more than one person is using the Print Checks and Forms at the same time?

Does NS really allow saving of these Checks with same check number if there are two users?

Indeed ... we tested it in Sandbox and got two different checks with the same number.