Now I never heard much disagreement from Powell, even ignoring the effect on the State Dept. of the vast changes Bush directed in our foreign policy- Powell had a couple of mild turf battles with Defense in post war Iraq.
You follow Israel much more closely than I do, admittedly there could have been disagreements there that I missed.
I think he did a good job on Iraq, departmental leaks aren't public pronouncements, which was obviously the most important. The largest number of "gaffes" did relate to the "road map", where he publically contradicted the President on critical points, critical to the non-existant peace process not the US, on several occasions.