If you are running multiple computers on a network, then the mail merge program will attempt to store all letters on the server computer so that all computers are able to access them. It has been doing this for about a year now.
However, due to network or windows security etc, one computer may not be able to write files onto the other computers hard drive. What the mail merge program does when it starts up is it attempts to write a dummy file onto the other computers hard drive, and if it fails, it switches back to writing all its files locally. It has been doing this for about a year also. This security issue is more likely to occur with Windows Vista, but XP and other windows versions can also impose security restrictions.
What is not so apparent, is when trying to print receipts or cheques/checks or inspection letters, it is also making this same check, because these operations all use the mail merge program. If it is unable to access the remote computer it attempts to use the local copy of the letters, which it may not have.
What I have done with the next version of the mail merge program is to display a message if you are using multiple computers and it is not able to save the files. This will only happen when you are opening the mail merge program, it will not do it each time it tries to print a receipt etc.
Extras for Experts : If you know what you are doing, you might be able to remove some access restrictions. Using windows explorer, right-click the Program Files\RentMaster folder and choose Properties. If you have a tab called Security, you can change it so that each user is allowed full control.