happened once, when had an opup. In fact they didn't have my choice of starter or main and in the end they concocted something from CW.
It was actually the worse flight we have had and truly wish they hadn't of bothered with the upgrade (were originally 64a/b) especially as they stuck us in the middle at the front.
However, last flight in F a couple weeks back, on avios redemption in OF, the CC ensured I had my first choice by asking if I could review the menu during take off, so that they can get my choice reserved before the 'others' hehehe well done BA!