I am experiencing pain mostly after running that feels like a burning sensation at times and sometimes a dull ache. It is located just under the Gluteus Maximus (or my ass) and above what I would consider my hamstring (the same hamstring I damaged several years ago). I have a lot less flexiblility in this area also. I am trying to attach a pic of the area also.

http://i2.tinypic.com/szfvyw.jpg