Not sure but some things to try...
Try forcing the focus onto the button or the window.
Run the script till it stops then NOT clicking on the button. Open the Object repository and see if QTP can identify the window / button in question. It may be that the window/ button identity changes with each opening
Try forcing the focus onto the button or the window.
Run the script till it stops then NOT clicking on the button. Open the Object repository and see if QTP can identify the window / button in question. It may be that the window/ button identity changes with each opening