Do I need to change bedtime routine?

[JosieO]

I have a 15 month old who until recently went to bed at night like a dream. The bath, bottle, bed thing worked great. She would normally get really sleepy on the bottle have a cuddle then go down.
Now, it's a different story. She screams hysterically when the bottle finishes and straightens out, stiff as a board. If I put her down she keeps screaming... i can go in and comfort her but if I put her down again she screams.
It's taking about an hour to get her to sleep and she always goes to sleep crying... should I change her routine?
Am I using a method that worked on a baby but won't on a toddler.
When alseep, she usually sleeps all night for 12 hours.
She has 1 nap a day - anything from 30 mins to 1 hour. But again it's a battle to get her to sleep, she'll cry when put down.
She's a great eater and always has plenty of food.
Advice please!

I seem to recall with dd that at this age we had to tweak her bedtime routine every so often - they're developing so fast. Maybe introduce some stories, tell her what's going to happen, and tell her she can have the last one when she's lying in bed - did this with dd and ds (using this book), so that there's an incentive to leave your arms, iyswim? It's worth experimenting a bit, but also tell her A Lot what's happening, and what's going to happen. Good luck.