sorry to be the one to not offer hope, but we're still fighting the 30 minute nap monster. I only get one long nap from my lo (if I'm lucky), which one is still not fixed either. But, I've tried, and I know she is sleeping less than she should, 'coz at night also she's sleeping only about 11 hours. So, we just go with the flow now. I leave her in the crib for 20-25 minutes after she wakes up from her first cycle, but if she doesn't go back to sleep, I just pick her up and go about our day. I wish she would nap longer, but can't do much about it.
Sorry, if this was more of a vent.
Sumita