>Ah, looks like I was wrong. The _VIEWSTATE field will always be present - but only contain minimal information it EnableViewState is false.
>This explains * what* it contains but not *why* : http://scottonwriting.net/sowBlog/archive/0000/00/00/162971.aspx
>You can also make the content completely empty by:

protected override void SavePageStateToPersistenceMedium(object viewState){}
>protected override object LoadPageStateFromPersistenceMedium(){return null;}

but I don't see the point...
>Probably removing the 'runat=server' would also suppress it ?

I finally got it to work. It seems to have been related to a syntax situation.