Some eastern Iowans are having trouble making phone calls after the weekend switching of area codes.Sunday marked the cutoff of the transition period during which either 319 or 563 could be dialed. But now some people in the 319 area code trying to call other 319 numbers are getting error messages, saying they should call 563. The error message is in error, according to Iowa Utilities Board spokesman Rob Hillesland. Dozens, perhaps hundreds of customers in the Iowa City and Cedar Rapids area were affected by the problem. Hillesland says several carriers are working on the glitch and should have it fixed very soon.He says anyone who gets the error message should call his or her local service provider.