hi:
what you mean by that? you want to install trixbox new version with a1200p , or want to use any particular version of trixbox. this doc is to use for trixbox without support a1200p in early days. now, the new version of trixbox can support a1200p natively, you do not need to do any compilation or hack that. i think the trixbox-2.5.07 supports the a1200p. please check from trixbox.org.
regards!
James.zhu