>I only buffer in underlying tables.
>But I'm wondering, if the underlying table is buffered, and a change to the data is done in the view, I need to do an tableupdate on the underlying table. If this is not done, when I rerun the view the data in the view is not up-to-date and if I try to change the data in the view again the update conflict error occurs.

You cannot buffer only underlying tables, views are always buffered, so you buffer both. I think you should ask this question first-do you need to have buffer in both. To my experience if you have buffers in both you should be doing it in purpose and take measures as needed, otherwise it turns out to be a mess.
Cetin