Are you sure that you have actually USE mytable command in the compiled code?
Maybe there is a comment line with continuation mark ";" right before it?

* Some comment ;
USE mytable

In this case foxpro would consider the second line a comment too.

>Under what circumstances VFP does not fails with error 1705 when tying to “use” a table in “Exclusive”?
>
>From the command window I receive the expected error. However, when I try to "use" such table from within my application, no error happens, it just keeps going to the next instruction.
>
>I’ll appreciate any hints.
>
>Thanks in advance and regards.
>
>Oscar Corte