Interestingly (!) not a mention of any problems on BAA's website, perhaps this has been blown out of all proportion?
"Terminal 5 opens for business (and pleasure) at 04:00 on 27.03.08. Designed by Rogers Stirk Harbour & Partners around people, not just planes, it’s going to make flying in and out of London as easy and enjoyable as it should be. New technology and direct transport links will make your journey simpler and faster. We’ve created shopping and eating that’s inviting, not intrusive. And with construction finished a new era for world travel can begin. Queuing, walking and waiting have made room for light, space and time - to relax, take in the views and rediscover the joy of flying."