Note that the polynomial factors completely into linears over \mathbb{F}_{16}. Notice that \mathbb{F}_8 is a degree 3 extension of \mathbb{F}_2, and \mathbb{F}_{16} is a degree 4, and \gcd(3,4)=1. That should get you started.
Thinking of this in terms of a http://en.wikipedia.org/wiki/Group_action" is helpful.
Showing that the centralizer of cycle a=(1,2,\dots,n) \in S_n, C_{S_n}(a) is equal to the group generated by the cycle of \langle a \rangle, is equivalent to showing that the stabilizer...
Here is an example in S_5. Take \alpha=(12345), and \beta=(13524).
They commute:
(12345)(13524)=(14253),
(13524)(12345)=(14253).
But they are not disjoint (and neither is one a multiple of the other, re Unviaje).