We have identified the cause of the popups not functioning properly on some Windows 7 PCs.
When the "Switch User" feature of Windows 7 is used, the application behaves different from when the Windows XP "Switch User" version. The Service keeps popping up on the first user that logged in and started a AmtPCClient. This has been identified as a bug and will be addressed by our development.
Workaround: Don't use the Switch user feature on Windows 7 for PCs that require popups.