[@netweb Keymaster 12 years, 9 months ago]

I think this is due to the following WordPress issue with custom post types:
https://core.trac.wordpress.org/ticket/12706

That said I haven’t looked at this closely in bbPress as it ‘should’ be ‘Update’ and not change the status to ‘Open’ as you point out.

Can you please create a ticket on Trac for this and we can either fix it or wait for the upstream fix via WordPress https://bbpress.trac.wordpress.org/