After reviewing your "Common Installation Issues" document I deleted the WinFileCache.dat file a couple of times along with uninstalling and reinstalling SecurityAssist several times.
What I kept seeing in Dreamweaver each time I reinstalled the extension looked nothing like the descriptions in the "Getting Started Guide."
I finally discovered that the documentation "Getting Started with SecurityAssist" I downloaded when I purchased SecurityAssist as part of the Dynamic Suite is for a different version of SecurityAssist. The Getting Stated Guide is for SecurityAssist 1.1.6 and the version I just purchased is 2.03
On the SecurityAssist webpage securityassist/
under the heading "How Tos" there is a link titled "How to apply Register/Login functionality to your checkout page.
Clicking on that link takes you to this page registration_on_checkout.php
that describes how to apply the register/login to the checkout process.
At the top of the instructions is a note about eCart and SecurityAssist along with links to "Getting Started Guides" for each application. The link for "SecurityAssist Getting Started Guide" takes you to this page
which is the documentation for the old application (v1.1.6 or higher) which unfortunately is what I downloaded thinking I was getting the instructions I needed.
You could eliminate a lot of users' headaches (literally) if you'd place the new documentation in that final link.