Have you tried doing a Manual Guide, to see if you can actually control your mount from within PHD?
From the PHD help file -
Manual guiding / mount testing
Want to know if these signals from PHD are actually getting to your mount? Or, need to manually guide your mount or nudge it? In the Tools menu, pull down Manual Guide and a dialog will appear that will let you move the mount at guide speed in any direction. Each time you press the button, a pulse of the same duration specified in the Calibration step size will be sent. Listen to (rather than watch) your mount to determine if the mount is getting the commands from PHD. The idea here is just to figure out if the mount is responding to PHD's signals. You won't be able to see the mount move (it's moving at guide speed) but you may be able to hear it. Other options include watching the motors themselves and attaching a laser pointer to your scope and aiming it at something fairly far away (to amplify your motions).