images dont show on Forms Authentucation page

I recently migrated an aspx website from IIS6 to IIS7.
Everything is working fine except the login screen does not show the images UNTIL you have logged in.
(we use Forms Auth and redirect to login.aspx)

I have the security on the images folder set to allow Everyone & IIS_IUSR account "full" access, but this has not helped.
I believe it to be either an IIS config problem or some sort of access rights.
I do have static content enabled in Server Roles as well.

I have trolled around these forums but have not come across it yet.
While this doen't seem earth shattering, it does look unprofessional.

 Any ides would be helpful.

Thanks in advance-
Don