I went through this with my daughter who is now 5 1/2 months old. She would go in great for a nap with her sitter, but not with me or my husband. The babysitter claims that she doesn't cry when she puts her down, just talks talks talks and plays until there is silence, or she simply falls asleep right after she's put down. We struggled with this for a while until finally, we decided that as much as we were against it, we needed to let her cry it out. Our babysitter happened to be out sick recently and when my husband was home with our daughter, he decided to try it. She cried for 15 minutes the first time then slept for over 2 hrs and cried for 7 minutes the 2nd time and slept for over an hour. Now when we put her down for naps, she usually talks/complains for a bit but eventually falls asleep. However, she doesn't always take super long naps, sometimes only 45 minutes. I think that the problem was that she wants to play with us rather than take a nap (understandably) and I would perpetuate the problem by constantly going in to check on her to see if she was sleeping yet, taking her out of the crib to try and rock her, then put her in and if she wasn't sleeping yet, pick her up again. It's definitely not easy to listen to her cry or complain, but we decided that we needed to do it because we knew she was tired and needed to nap.
Also, the doctor recommended not to go into her right away if she wakes up after a really short nap but to leave her in there for a little to see if maybe she'll fall back asleep on her own.
If you don't want to let her cry, I would suggest you try to avoid picking her up.
Good luck! I know how frustrating this is!