SAVE AS: a warning message says it can't save

[teo]

I have a Web Form with a Button on it,
nothing more.

I load the page from VisualStudio2005 Asp Net 2.0 enviroment
(with internal server)
and immediately go to Save As... the page
all is ok.

Again,
I load the page from VisualStudio2005 Asp Net 2.0 enviroment
(with internal server)
I PRESS THE BUTTON (non code behind it)
and go to Save As... the page
but
a warning message appears
(at the left-top of the browser) saying about
it can't properly and completely save the page.
There are also: the question 'Continue?' and two YES/NO buttons.

If I chose YES the page is regularly saved.

----------

Two questions:

The Button, indeed, will have to do a lot of job
and populate some Labels, so I need to press it.
How can you avoid that nasty message to appear?

It seems the page is properly saved,
so in what cases there will be loss of content in the saved page?

 

[teo]

nobody for this problem?