Actually, this did NOT solve my problem. It did up my success rate, but getting something to print is still very hit-and-miss. Since I am using the same SD cards with 100% success from Makerware, I don't think it is the SD cards themselves that are the problem.
What happens is that the print will begin by moving the extruder to the near left corner. It will spurt out a blob of plastic and then move to the general area I told it to build on. Then it will just sit there. There is no status on the LCD panel, it simply shows the file list. The extruder will sit there, hot, fan spinning, and slowly leaking plastic until I either shut the bot down or start another print.
I like S3D Creator a lot, but am frustrated that I can't get consistent behavior from it. I am willing to concede that is may be something on my end, but since I have a 100% success rate doing essentially the same thing from Makerware, I have no idea what that might be.