Our DS is only cat napping during the day as well. The only thing that I have found that works is if I let him lie on me. I can usually get a good 2-3 hour sleep out of him that way because as soon as he stirs I can pat him and he settles again quickly. Today though has been a nightmare. He is so tired and we cannot get him to sleep at all. I hope the phase ends soon too. I've heard that they're supposed to just start sleeping through their 40 minute cycle at some stage (maybe 6 months???) because they can get themselves to sleep. I'm not sure how to speed up this process. Good luck with your little one.