We have installed SolidWorks 2005 SP 0.1 and PDM\Works 2005 SP 0.0. Everything is working fine for us. We reboot the PDM server once a month to keep things linked, just to be safe. We upgrade each 2004 model, drawing and assembly as we work on them and put them back into the PDM as 2005. Opening SolidWorks 2004 files have not been any trouble at all.
Bradley