What is TestComplete doing differently to user?

Our test application uses a mix of windows and code-jock controls. I double click a menu item in a SysTreeView32 to open a form with code-jock tab header inside an MDIClient. I can open several forms in this way and they all appear as code-jock tabs within the same MDIClient object. I can close the forms and open new ones.

When I do this with TestCompete I can open the forms and close them but when I try to open any form after closing any other form the tested application crashes.

This happens whether I run a test script or simply have the test recorder running while I perform the actions manually.

I don't understand why the tested application performs fine when I do these actions but crashes when TestComplete is playing or recording.

Does TestComplete do anything differently to a user action (like lock certain objects or settings)?