#136 Broken integrate() function

[Eduardo Sánchez Muñoz]

If I write "integrate(1/(x^2+1); x; 0; 1)" I get "Argument 2, Variable of integration, in integrate() must be an unknown variable/symbol.", but the second argument is x, which is a unknown.
However, with other expressions like "integrate(sqrt(x); x; 0; 1)", I does not throw any error.