I'm interested to hear replies. Our son is up to the same tricks! From 4 weeks until about 3.5 months he would sleep a 6 hour stretch at bedtime have a feed and then sleep for 3 hours more. For the past month, he wakes up 45 min in if he is overtired (at least we've figured that one out and know how to avoid it or when it's coming) then again between 10:30-12:00 sometime but for no apparent reason, he isn't hungry, just can't fall back asleep on his own! This is weird because he falls back asleep on his own at other times through the night and during naps. After that wake up, he usually will sleep for a few more hours until it's time for his feed but after that feed he sometimes will wake up every hour, sometimes goes to sleep on his own for those, other times we have to go in and pat him. It is very inconsistent which is why we don't understand it! Last night he slept right through until midnight, again until 4:30 when he had a feed and then until 6:30 when he got up (bedtime is between 7-7:300 but the night before he woke up 8 times!!!!