Hi Edgar,
I thinnk that Ed has given you clarification on the solution to your problem. I just wnat to point out that in order to create a single instance application one doen't have to pass a form caption. All you have to do is pass a string that's going to be unique on the machine the application's br run on. This could be, for example, the fully qualified filename. This would solve the problem of starting a second instance of the application if there was no form to get a caption from.
George
Ubi caritas et amor, deus ibi est