> when using comctrl32.ocx in our vfp9 app.

Is the control in the application directory? If not, put a copy there. VFP can load unregistered controls when it finds the OCX file and the control has no dependencies.

>do u know how to troubleshoot this please ?

First you would need to know if the registration of the control in the registry disappears or is altered. If a program on the server keeps changing the registry, you need to identify this program.