I posted recently about this and thought it was my DV, but I reckon it can't be:
Just driving normally, then on a random occasion there is no boost. No CEL's. Car still drives, but the turbo seems to have been neutered. I assume it must be some sort of limp mode. If I switch the engine off and on again it's fine and boosts normally so it can't be a loose hose or anything mechanical (I assume).
Has happened a few times this week.
Strange one