Created attachment 131910 [details]
I noticed that if i am painting in an active selection with a colour smudge brush that the opacity of the stroke is changed to a lighter one than it should be. I don't usually paint within active selections, it was purely by accident I noticed a change in how I expected the brush to have behaved (In had edit, select all marquee active at the time without realizing from an earlier select-copy and paste).
I've attached some screen shots.
*** This bug has been marked as a duplicate of bug 423851 ***