Add-ins not loading when opening MS Access 2007 a second time

I have some add-ins that are used with an MS Access 2007 .accdb application.
When I open the .accdb file --the first time-- (after logging into the PC),
the add-ins initialize successfully. If I then close MS Access 2007, the
second (and subsequent) time(s) I open MS Access, the add-ins do NOT
initialize.

They will load, however, if the user clicks on the MS Office Button > Access
Options > Add-ins > "Manage: COM Add-ins" > [Go...] > [OK] (Or [Cancel])

1. Is this a bug? Is this expected?
2. Is there some way (with VBA code) to force the Add-ins to initialize?

Thanks!!