[Maxima] integral of 1/(x^4+3*x^2+1) fails

[Robert Marik]

Hello all, Maxima fails to evaluate integral of 1/(x^4+3*x^2+1) .
However, I think that this integral is quite simple (partial fractions
and two arctangent). Whats wrong?

Maxima is not able to factor the denominator. Is this point the source
of the problem? (btw: factor_with_solve factors the expression in the
field of complex numbers and maxima evaluates integral after this
factorization).

Should this be reported as bug?

Thank you.

Robert Marik