swarf,
First off, I would not run from the floppy. It takes to long to read the file and the cutter will sit in one spot turning and doing nothing = ragged cut.
What is the file extension of your g-code file? What extension do you have setup in your ini file as the extension of you g-code files? Bet the two are different. Personally, I have my cam program and TCNC setup to use .txt files. This way, I can look at and edit them in notepad real easy. Then when running, I load them into the editor and run that way. Again, then all is in memory (if you have enough) and won't have to do disk reads. My Ini file is setup to look at the cnc directory on the c drive. If you have various directorys under that, use the tab key/arrow keys or the mouse to move around (assuming V4.x)
Art
AKA Country Bubba (Older Than Dirt)