View Definition edit doesn't work???

View Definition edit doesn't work???

Hello,
I'm trying to edit a view using the Definition screen, while I can't find the way to setup up the view criteria without using the builder (I would want to use a free code page).

Any edit I do in the definition file, even NOTHING, and SAVE, the view resets itself, losing all my definition setup.
I edit, save (without touching anything), and come back on the definition page, and the code is reset as It was a new view page.

Why this?
How can I modify a view quickly without risk to lose all my definition work?

please try using my app PRODUCTION and view PAYROLL 12-2013

many thanks.
Claudio