hi,
you mentioned you checked for drift with two stars, one in the west and one overhead??
you need to watch drift on a star at zero dec and intersecting the meridian, not overhead. thought I'd clarify that.
and the star doesn't need to be bright. its very unlikely to get a bright star at below 25deg east/west and zerodec/meridian. so just use your guidecam in your main scope and loop 1second exposures.
the new version of phd (phdv2) has a module for this.
http://openphdguiding.org/man/Tools.htm#Drift_Align
Cheers
Alistair