This problem seems to occur for some users if your IIS server does not have a .snp mime extension.
To resolve this issue go to:
Control Panel -> Administration -> Internet Information Services ->Right-Click your "AccessReporterSample" Folder ->
Properties -> Http-headers -> MIME Association -> Registered File Extensions -> Click the "New Extension" button.
Write ".snp" in the "Associated File Extension" textbox, and "Access Snapshot Viewer" in the "Contains (MIME)" textbox.
Click the "OK" button and PRESTO - NO MORE PROBLEMS!