Debugging the flowchart example

[Nick]

Hallo,
I am modifying the Flowchart Sample from the Visio 2003 SDK and would like
to debug it.
I set the Start Application to the visio.exe and started to debug.
Visio appeared breifly then disappeared. Upon retrzing this action I got a
dialog box containing the text

Visio experienced a serious error the last time the add-in 'flowchart sample
(c#)' was opened. ...

Any ideas how I should be debugging this add-in?

Many thanks in advance.

Nick