[Maxima] strange behaviour with simple decimals

[Barton Willis]

Some of you might be amused by:

(%i1) d(x) := cf(rationalize(x))$

(%i2) d(0.2^2 - 0.04);
(%o2) [0,144115188075855872]
(%i3) factor(%);
(%o3) [0,2^57]

(%i4) d(1.3^2);
(%o4) [1,1,2,4,2,2,1,592578898337,1,1,18,2]

Barton