TEC 3.9: change from ACK to OPEN ?

Hello,

Looking at the documentation for set_event_status and change_event_status,
I see that it doesn't allow changing the status of an event from ACK to
OPEN. is there any good reason for that limitation?
I was using 'ACK' for effect events and wanted to change it to 'OPEN' when
the cause is resolved but not the effect.

Thanks,
Salutations, / Regards,

Francois Le Hir
Network Projects & Consulting Services
IBM Global Services
Phone: (514) 964 2145