>I think I have solved this problem now.
>
>It looks like it was because, oDS, my object reference was going out of scope when the forms load event finished.
>
>I have made oDS public now and all seems ok.
>
>Should I have made oDS a property of my form instead of a variable.
>Would this slow things down?

Yes, a form property would be the preferred way to deal with something that only belongs to the form. A PUBLIC variable could cause you trouble. No, I doubt that speed would be an issue here.