both of those pages have rather long forms on them, so that is probably the cause of the first error, it's just taking a while to inspect them form when the page opens.
does the Access Manager work for other pages? It only errors on these 2?
Can you try adding the Restrict Access Server behavior to those two pages rather then using the access manager.
open each of them and go to the server behaviors panel, click the plus button and select webassist -> Security Assist -> Secure Page.