Randomizing random?

Hi,
I'm using the math:random function from EXSLT from within xsltproc,
but, well, it's not random, it always returns the same sequence.
random:random-sequence does not seem to work in the same processor;
this one includes a seed to randomize output, I guess.
In any case, how can I randomize math:random?  There's no
math:randomize, no way to feed it a seed (which I wouldn't know how to
get in a (pseudo)random way, anyways... Is there any other option?