It's a real common thing curt. I've been through 3 chronarchs that Shimano has just replaced for me over the last 6-7 years. Shimano seems to be real good about making things right, especially if you send it to Shimano it's self.
Have also had the same problem your talking about with my Calais. They're the smoothest when you get them but after 100 fish or so they do start to get a little catchy.
Keith