Sounds more like he has the switched and permanent feeds wired the wrong way round (is he in a VW? This is, after all, one of the FAQ points).

I think it would be a better start if he could verify that the permanent feed *is* permanent. And no, please don't say "but it only happened after the upgrade!" or I think I will jump off a cliff.

Do the measurements on the perm and switched 12V first, and then accuse the s/w afterwards.