M.B.
I agree with the other two posts. I have a 13 month old and she and I STILL fight about naps from time to time. I'm sure it will continue. When she is at MDO, she naps without crying. When our mothers or babysitter take care of her, she also naps without crying. Granted, mine is older, but we have stuck to the same sleep routine since she was 4 months old and I am convinced that consistency really does matter. Sometimes, she will snuggle in her crib and go down like an angel and other days, she is just so upset when I leave the room.
I think moms have a part of their hearts that dads just don't have. Not that it's a bad thing, of course, but my husband does not get the heart pounding, stomach turning, near-panic attack I get when she really wails. The guilt is hard, but take it from me - 8 months down the road - you will be glad you stuck it out.
Something I read has really helped me cope. One of the books suggested that if they cry for more than 30 minutes, the nap is over anyway, so go ahead and get them. Mine has yet to make it to 30 minutes. I think the closest she has been was 20 mintues. It's a long 20 minutes, but then she sleeps great!
You are doing great - keep it up!