Do you have a routine that is enjoyable for your LO? I just recently had to start a very strict routine with DS and it seems to be helping with the night time battles a little. We read a story or two downstairs, head upstairs, brush teeth, change diaper, get jammies on, nurse, sing lullabies, and he snuggles onto his sheepskin and holds his baby (doll) while I finish up with the lullabies and rub his back and face.
I know it doesn't sound as involved as some routines I have read about on here, but he knows what it all is leading up to, and he seems to enjoy most parts of it, so he looks forward to bedtime.
Maybe you could change your routine if you have one too? I know that DS sometimes needs to have things shaken up in order to stay on track occasionally.
Not sure if this helps, but it definitely sounds frustrating.
Formerly single Mama to the zaniest boy on the block, born on my birthday on 3/28/07. Soon to be Mama to a new little and can't wait to and and again!