[XenonSurf]

[EDIT]


Should not happen with the VIIA, because it's the default sub when you start and when you don't have the VIIB-Start mod installed. But then: I don't know exactly at which point you get your sub upgraded, other players will have to join-in here.

With the VIIB you may remain stucked with it, and it would be because of this:
In order to enable the VIIB at start, you need to load the optional mod in TWoS first. But then, before a new campaign chapter starts (or better before you enter bunker next time), you need to REMOVE this mod again, else you stay at VIIB...
That's just a theory of mine, I'm not quite sure that this will happen.


So maybe you have the VIIB mod installed and have a VIIB, not a VIIA ?
You can know for sure by going in the file 'Playersettings.cfg' in your savegame folder, or by simply launching KSD Commander.