After reading Eric's "how to" article on using the DSI with Meade's Envisage and LX200 emulator software, decided there must be an easier way and looked around for another solution for non-Meade mounts.
Discovered PHD Guiding has a new (stable) pre-release version with DSI support.
http://www.stark-labs.com/phdguiding.html
Tried it for the 1st time last night. Selected the DSI and Shoestring adapter (GPUSB) from dropdown lists and pushed the Guide button. A short automatic calibration routine and then everything worked perfectly straight up. Highly recommended.