I have been installing a lot of new SCCM 2007 sites lately and used my step by step guide. In my guide I configure Webdav settings needed by SCCM before starting Configuration Manager installation.
When SCCM tries to install Management Point (MP) it fails and in the setup log it says that the WebDav settings are wrong even if they are set correctly?!
Solution is to re-set all the four needed values, apply settings and restart IIS services. Next time MP installation will retry it will success..