Right I seem to have become idolized with a few factions without even doing anything for them since the last rep gain. Same thing has happened with vilified factions so I'll just list them:
BoS
Liked-->Idolized (not done eyesight for the blind yet)
Great Khans
Accepted-->Liked (only thing I did for them was peacefully let them escape from Boulder City no contact since)
NCR
Liked-->Idolized (again can't see what quest/freeform I did to get to Idolized and I didn't even receive the message saying I was)
Powder Gangers
Vilified-->Merciful Thug (not done any quests with them to gain rep)

The last quest I completed was Beyond the Beef. I ousted Mortimer and was given White Glove rep along with rep with the Strip.
I am currently not wearing any faction armour and I tried to fix the bug where the pip-boy doesn't update but that doesn't seem to be the cause.

Any ideas?

Cheers