Yep, I'm going to jump on the bandwagon too. My 7mo does the 30-40 min nap thing. She had been having one longer sleep of 1 1/2 to 2 1/4 hours more recently but in the last few days that seems to be out the window, along with any notion of an afternoon sleep at all some days.

She goes down at around 7 at night, and having slept right through til a feed at 4am for ages, for the last 6 weeks or so her night waking is getting more and more frequent. She usually resettles quite easily and sleeps til 7-7.30 but 1 morning in every 4 or so (this morning) she'll wake at 5.30 and refuse to go back. At that point I always take her in our bed so that I can doze while she bashes our noses/pulls our hair etc!

I'm holding out for crawling because I think that may well help, but I fear it could get worse before better. I just keep reminding myself that 'this too shall pass'!