ASP.net requires "Users" permission to Temporary ASP.NET Files even when no impersonation is required

Hi,

Recently our users cannot access aspx pages in our website. Days before it was working properly. Found out the solution was to give "Users" group read permission to "Temporary ASP.NET Files" folder.

I'm wondering why suddenly this permission is required. Our website does not have impersonation configured. So by right, HTML pages will run under IIS_<machine> user and ASPX pages will run under Network Service user.

Server: windows 2003 IIS 6

Any one can give some enlightment?

Thank you.