I have a default.aspx page that is detached from the page layout and I am
getting this error every time I try to edit the page/edit content editor
webpart:
"This Page has been modified since you opened it. You must open the page again."

I have tried adding this code to the default.aspx page and the masterpage and it
didn't help in either case.

<script language="javascript" type="text/javascript">
if(document.getElementById("MSO_PageHashCode"))
{
document.getElementById("MSO_PageHashCode").value="";
}
</script>