Sounds like the course change is normal according to the Aviationist:
Between 17:19 and 17:20 the aircraft turned right, changing heading from 25 to 40 degrees. Someone said this is a sign the aircraft was turning back to Kuala Lumpur or had already experienced an in-flight problem. However, the change in heading was probably performed in accordance with the FPL (Flight Plane) as the plane did the same, at the same position, on Mar. 4, 2014.
The Aviationist » What we know and what we don’t about the mysterious Malaysia Airlines MH370 disappearance