DD is 7 months and is having terrible sleep since she got a bad cold about a week ago. She's sleeping from 8pm til about 3.30am and then is pretty much only going back to sleep when held. Any time you put her back in the crib she absolutely wails, no matter how asleep she seemed to be in your arms a moment before.
She was an all night sleeper from 4 weeks until about a fortnight ago so I guess this is my time coming for all that sleep. 
DP reckons she'll go back but I'm not so confident...