There's a big thread on this here http://www.flyertalk.com/forum/briti...flight-26.html.

A few months back I did GLA-LHR tagged on to a redemption in CE from LHR-CPH a couple of weeks later. In MMB (as is the case with everyone else) it does say that you have lounge access at GLA. However, at the lounge they said that technically I wasn't allowed access as the connection was more than 24 hours. I showed them a print out of MMB and they said "yes we know but MMB is wrong, you're definitely not allowed. However on this occasion I'll let you in".

So we did get in eventually, but they were fairly adamant that you're not meant to be there and it seems many people haven't been as lucky as me and have been denied access.

Seems ridiculous, I think that BA should honour whatever MMB says. Who cares if their IT is at fault, that's their problem. I wouldn't care about not getting lounge access on a redemption connecting flight if MMB says I couldn't, but the fact that it says you are allowed is what makes it so frustrating.