I'm right there with Ian, that's really good advice. Also, check out the new tire set up carefully, make sure they put the tire on correctly (the old red dot to tire stem check) and didn't manage to fold the tube which can cause those exact symptoms. Might put her up on a stand and deflate the rear tire and reinflate just to be sure. Ohterwise, spoke tenson, wheel true, etc like Ian said.

A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. Herm Albright (1876 - 1944)