Maxima problem with ASSUME_POS:TRUE;

Dear Coleagues,
  I have been developing an interface to allow students to use maxima on
their pages  in a "wiki" manner.
(see
http://aamorimsrv.fis.fc.ul.pt/tikiwiki/tiki-index.php?page=maxima_plugin)

In the maxima plugin I invoke maxima with the argument: maxima
--batch-string="    "
I also prepend the message to process by ASSUME_POS:TRUE;

Anyhow when I include integrate(x*log(x),x,a,b); the system stil asks me
is a-b is positive, which in the web case just means that the server is
left to timeout.

Is there a better way of forcing maxima not to ask interactiva questions?

I am using  maxima 5.9.1-7 on a PC running linux Debian.

Thank you in advance,
Antonio Amorim