What's VFP version/SP? What's Windows version/SP?
As a workaround, you may consider shutting down and restarting your application once a day.

>Hi,
>
>I had 03 application using timer to check for some file to unzip and
>post. All 03 application are running independent of each other on the
>same system.
>
>After maybe 01 or 02 days, it give illegal operation on maybe
>one of the application, on click, it cause other 02 application
>to give illegal operation too.
>
>My application normally just unzip or zip using dynazip activex
>control with Application.AutoYield = .F. when zipping or unzipping,
>then set Application.AutoYield = .T. again on exit.
>
>Any way to know check or know why my application give illegal operation
>error, I suspect of memory leakage problem.
>Please advise.