L.C.
have you tried putting together a new bedtime routine? My sister had a similar problem and so when she made the switch t the toddler bed she createsd a new night-time routine that was a little long, about 45 minutes, including all the usual things like a bath, 2 stories and some back rubbing. Of course, the first few nights were tough but it didn't take long for her to see that the new bed came with a new routine and she settled right int it. Kids love structure, but they like it to come in such a way that they think they are maing the decision.
Hope this helped!