Thanks. I have him on the 3.5hr routine (he's 13weeks) and bottle fed. The times vary but the only difference to the 3hr routine except for the extra half hour is the evening feed; 5:30 and cluster at 7:30 and usual df at 11 (although he sometimes doesn't take it because he's full from the cluster)
The routine changed recently but that's not the reason he sometimes takes short naps; it's always been sporatic. Some days each nap is 2hrs long, the next they're 30mins...no two days are alike and I'm getting frustrated because I can't leave the house in the afternoon if he napped poorly in the morning.
To be honest I feel house-bound my this routine...but he needs to sleep, he's always exhausted and I feel bad that I can't help him.