Not a bike issue but a wheel issue. With your current mileage it's about time for a good set of hand made custom wheels. I'd say wheel building is 80% wheel builder and 20% components. Excellent wheel builder with so-so components would result in a better wheel than top of the line components put together by an amateur. It's not rocket science, but there's a bunch of easy-to-make mistakes and easy-to-miss details that make the difference between worry free riding and recurrent back and forth trips to the LBS because of wheel issues.

I'd begin looking for a good wheel builder (local preferably) and start there. He might even let you get some more miles out of your current wheels.

Good luck!