I solve the cubes in a way much different than lots that people have explained:

(Don't read if you don't want!)

I pick a "top" side and solve it.
I put the centers together(on the order 3, this was REAL easy! :-)
I put the edges together that go from the top to the bottom.
I solve the bottom 4 corners
I solve the bottom 4 middles.

depending on which cube, the 2nd and 3rd steps are switched.

I am only having one problem with the 5x5x5 cube, though:

X|O|X|X|X
X|X|X|X|X
X|X|X|X|X
X|X|X|X|X
X|X|X|O|X

looking at the bottom of my cube, the 2 pieces marked O are swaped
sometimes, so that the face is still a solid color, but the sides are
swapped.

I also got it to have the swapped pieces near each other:

X|X|X|X|X
X|X|X|X|X
X|X|X|X|X
O|X|X|X|X
X|X|X|O|X

My question is this:

I can't figure out what causes the swapping.
Is it the because in this face,

X|X|X|X|X
X|O|I|O|X
X|I|X|I|X
X|O|I|O|X
X|X|X|X|X

the I's and the O's are in the "wrong" positions, even though they are
indestingiushable?

Dale Newfield