Refactor is very useful in my work. But I found that "rename" only works in the file that opened. For example, if I want change variable "point" to "m_point", variables in the .cpp file had changed, but still remain "point" in .h file. I think "rename" shoule change all variable names in the Project(Solution), not only the .cpp file. A plugin named ref++(http://refpp.com) works well. But the speed is too slow to stand.
Can you try running Find References on "m_point" and see what happens? Rename uses the results from Find References to do the code changes.
I use rename quite a lot, and it always updates all of the files for me. Are you using source control, so that the .h file is not yet checked out and is marked as read only?