Permission to use object denied

I have written a program designed to be run of a network drive. However whilst most of the computers on the network run the program with no problems, some come up with the error "Permission to use object denied" when trying to load the main screen. This might have something to do with the inclusion of the MSFlexGrid but I am not sure why it is working on some and not others. I have added all the relevant OCX's etc to the directory the exe is contained in so this should not be a problem.
Thanks.

Is this a NT network? Have you or your Sys Admin go into Admin Tools and then User Manager for Domains and look at the permissions that users are allocated.