Here are collection of web articles to troubleshoot a RODC:

Introduction: http://technet.microsoft.com/en-us/library/cc732801(WS.10).aspx

Read-Only Domain Controller Planning and Deployment Guide: http://technet.microsoft.com/en-us/library/cc771744(v=ws.10).aspx

AND also: http://technet.microsoft.com/en-us/library/cc754956(WS.10).aspx AND step-by-step: http://technet.microsoft.com/en-us/library/cc772234(v=ws.10).aspx

On branch office with RODC and client computers running XP or W2k3 servers, apply the patches here: http://support.microsoft.com/kb/944043

http://social.technet.microsoft.com/Forums/fr-FR/windowsserver2008fr/thread/62c52d0f-dbda-46cb-9860-3953a0cb00f5/

http://technet.microsoft.com/en-us/library/cc732322(WS.10).aspx

http://www.winvistatips.com/re-authentification-win2k8-r2-inter-site-t809529.html

In French the article from Benoit Sautiere: http://blogcastrepository.com/blogs/benoits/archive/2009/10/19/quelques-subtilit-233-s-autour-du-rodc.aspx

AD DS RODC: http://technet.microsoft.com/en-us/library/cc732801(WS.10).aspx

Montoring – Password Replication Policy Administration: http://technet.microsoft.com/en-us/library/cc753470(WS.10).aspx

Understanding RODC authentication: http://blogs.technet.com/b/askds/archive/2008/01/18/understanding-read-only-domain-controller-authentication.aspx