You are definately not alone.
My lo is now 6.5 months old. She suddenly started fighting nap time with a vengence about 2 weeks ago.
What I did was extend her wake time. I was putting her down at around 2 hours and 15 mins...but when she started fighting me, it was 2 hours and 45 mins before she finally went to sleep for her second nap, and 2 hours and 30 mins for her first. She seems soooo tired around 2 hours and 20 mins, but she refuses go to sleep. So I'm just keeping her up rather than fighting her. After she goes down, she takes a 1.5 - 2 hour nap, so I know I must be doing something right
It was like an overnight change.
So now she's officially up to 2 hours and 45 mins. She still fights a little bit, but she's starting to just drift off to sleep like she use to. I think part of it though is the developmental changes...she's become more aware of her surroundings, wants to play with her crib animals more, teething (she has 2 teeth in now), and more recently, she had her shots, including a flu shot, so she's been a little sick for the last few days. Also, she's dropping her third nap now because of the extended wake time.
So, just thinking, it might help to extend wake time slowly by 15 mins every few days. Who knows? That could be the problem.
Hope this helps a little!
*HUGS*
Sonya =P