[Centos] problem building the isos?

Hello all, I am making my own distribution based on RHEL AS 3U4 (with additional rpms, like urpmi, webmin, nessus, Maildir format by default for Postfix, courier-IMAP etc.) and I would like to have information from the CentOS team. I am generating the isos of this distribution but during the launching of anaconda, the graphic interface failed to work, so the installation in text mode is the only one possible. I think i find the problem: pam. by using pam-0.75-51, all is ok (graphical install of anaconda) but with more recent versions, anaconda refuses to launch the graphical install. Question: had somebody similar problems?? Thank you in advance and good year to all :)