I use a DSIPro/PHD at present.
Are you using a 2X Barlow? Good enough focus, and correct camera orientation; N/S, parallel E/W ?
Powered on USB Hub, or USB direct ?
Frame chew/buffer reqs seem to cause grief with shared USB over powered HUBS.
PHD tips here:
http://www.stark-labs.com/wiki/doku....ec_calibration