Stubbed message reconstruction - Works Under 32-bit Win 7, not 64-bit Win 7? (ArchiveManager 4.5)

Sorry if this is answered elsewhere, but I could only find info on version 5.3, 5.4 and 5.5 in the Support section of the website.

In our organisation we've got Archive Manager v4.5. On our Windows 7 32-bit machines, when a user first clicks on an archived email, Outlook installs the AfterMail v4.1.1 form and the content of the email is displayed in Outlook (stubbed message reconstruction working correctly). But on our Windows 7 64-bit machines, when Outlook installs the AfterMail form, the body of the email just displays "This message has been archived, please click here to view the message".

I'm not sure if the 32-bit/64-bit OS difference is actually the cause of the issue, or whether it's a coincidence. Both systems are running 32-bit Outlook 2010. The documentation here (https://www.quest.com/products/archive-manager/) does indicate that stubbed message reconstruction works with "Microsoft Outlook 2010, 64-bit or 32-bit, running on Windows 10, 8, 7, or Vista SP1", but I thought that might only apply to the more recent versions of the product. Looking at the Form Properties in Outlook, it only lists "WinNT3.5 (ix86), Win95, WinNT4.0 (ix86)" under Platforms, and looking in the 4.5 User Guide the Outlook Form only lists "MS Office Outlook (version 2003, 2007, or XP)" under compatibility.

If anyone can confirm whether 4.5's Outlook Form should work on a 64-bit Windows 7 machine running 32-bit Outlook 2010, that would be much appreciated.