Centipede/forrest out of memory error

Hi all,
    during the building of my site (the site target)  I get an out of memory
error.
It just bombs out during the creation of the HTML pages, with no stack trace
or anything.
I am running checkstyle, umldoclet, junit tests and javasrc on my code, and
the problem goes away if I dont try to run all of them at once.
Where should I be specifying -Xmx and -Xms as, from what I can see, Java
gets called from a few places, or is this even the problem?
I have tried setting it in cent and in forrest.build.xml but to no avail.

Thanks for any and all help,
Paul.
Paul O'Neill . · ´ ¯ ` ®
Software Engineer                DDI: (01) 2400 522
Point of Sale Solutions         Tel:(01) 2400 500
Sabre Holdings                    www.sabre-holdings.com