Note that this does NOT happen by itself, some of Your code does this.

First of all, make sure that you have Exclusive=Off in your config.fpw file. Secondly make sure that you never include any DBF in an exe or an app. And last, if you open a table more than once, the attributes you used the first time will be the active attributes on subsequent uses of the table. In an application you normally don't open a DBF exclusive, in my applications I NEVER do.

You only need exclusive access to a DBF when you want to create an index tag, or when you want to pack the table. Both of these commands should ONLY be used in a maintenance program which is run once or twice per year, not more often than that.