Hi Piet,
we had a similar problem: with outlook 2003, after 3 times the preview would not make an e-mail any more...
Restarting the pc resolved the problem....
I am not an Office-specialist but i think this is an Outlook-problem. Because if the user had that problem, he could not open any more attachment, it was even impossible to save attachments in an e-mail. Sometimes he only had to restart Outlook, mostly it was the pc wha had to be restarted... so: this was nog really a solution.
Searched on MSDN and found some issues, mostly security, one issue solved our problem, decribed in: [
www.howto-outlook.com]
I do not know if yours has the same circumstances.... but it is worth trying...
Best regards,
Geert