>Yep, tried that. I think this is a memory issue as it works on a *clean* form on my PC but not within the application. Although the navigation menu for the system is also a treeview. The PC I use here dies at least once a day so I know there are problems with it.

In that case, have you tried loading the lastest DLLs and stuff? Can you find different versions of:

OLEAUT32.DLL
OLEPRO32.DLL
STDOLE2.TLB
MFC42.DLL

on the computers that work and don't? Just guessing here, basically any file that has OLE in it may need to be check then.

This is from an ActiveX FAQ for one of Mabry's products:
***
Frequently Asked Questions - FoxPro


Why don't events fire in FoxPro 5.0?
There can be a problem with with VFP responding to events. Be sure to set AutoYield as follows:

_VFP.AutoYield = .F.
thisForm.FTP1.Action = n
DOEVENTS()
***

The middle line obviously doesn't apply, have you tried a DOEVENTS()?