Sometimes I will dislike a character on first reading but when i go back and reread that book, I end up liking them. Sometimes I think characters just need to settle within you. Or a book has to settle. It needs perspective. (For instance, i didn't really like Tuon on my first reading of her but once I read her again, I decided she was alright.)

I usually don't go from liking/disliking a character and changing my mind as the series goes on. Min from WOT is about the only exception I know of and that's because her character has had such a drastic change from being a self-sufficient and confident woman to one who is willing to be controlled and to sand by while her man makes all the decisions.