Is anyone else having a problem where VOXATC constantly switches back and forth between two ATCC frequencies? Example... on a short flight from KMDW to KDSM, after contacting Chicago Center I am asked to switch to Chicago center on a different frequency. About a minute later I am asked to switch to Chicago Center on the original frequency. This continues back and forth every minute or two until I am given instructions to switch to KDSM Approach. It's making me crazy!