testing ibpdv and ibpu

[salvomic]

hi all,
I'm testing the "integration by parts" in the Prime.
Inputting ibpu(x*sin(x),x) I get [-x*cos(x) cos(x)], ok
with ibpdv(x*sin(x),sin(x) I get [x*sin(x)^2/cos(x) (-x*sin(x)^3-cos(x)*sin(x)^2-x*cos(x)^2)/cos(x)^2]
I'm a bit confused: shouldn't I get the same result as above? Am I using wrong syntax? :-)

Then another question: there is also a "integration by substitution" method in the Prime?

thank you
Salvo