Not going to waste my time contacting BMW direct as everyone who's posting seems have been told the same advice: for e90's we need to wait the 8 weeks (or so) until it's been trialled on the X5/6.
So I guess it's grin and bear it for the moment...
A bit of a result having Watchdog on the case though as this issue has been dragging on for f**king months now with BMW refusing to acknowledge the issue, so IMO this is progress at least.
Still, taking no chances: my OBD2 port is staying hidden and I'll be using my Disklok at all times.
It's gone - no longer an e90 330i owner