Are you sure this is not just an issue in plsql/developer.
I have asked a oracle expert who as never heard of this problem, and posted messages on oracles own bb, and recieved the following replys
"Hi,
PLSQL developer does not recognise triggers on views.
If you edit the view with PLSQL developer, the triggers will not be created as a part of the create or replace script.
You could create a script that recreates any view triggers, so that it can be run after any PLSQL developer recompiles."
"Hi,
I think that the problem is in the product.
That there is no concideration that there could be a trigger on a view, so they are not taken into account.
I use Designer 9, and because it creates the view and then the triggers separately there is never a problem.
But Designer is not a useful tool for tweaking a view in the same way that PLSQL developer is.
So: 'tweak' in PLSQL developer, cut and paste into Designer and generate out. A bit long winded."