Doug I do exactly as you have explained and use both programs open at the same time, all the time, using the 5D and the 30D hooked up at the same time as well, and jump from one to the other, when needed.
I even down load my images while both are open, so i can inspect for errors in focus and stuff like that, don,t know mate
then continue on to my target when happy with the images.
I reckon it is in the USB cable itself, but that is just an assumption.
Leon
