If you get the following error while exporting to a Quicktime file from Final Cut Pro:
"Codec not found. You maybe using a compression type without the corresponding hardware card,"
check to see if you have an image file in your timeline that is using CMYK mode rather than RGB. CMYK will throw this error and possibly cause you a lot of headache wondering why.
If you find that you have a CMYK image in there. To find out just select the image in the timeline, right click (or option click) and choose "show in finder." Then right click (or option click) on the file and choose get info. The color mode should be shown in there. Then you'll have to open the image in Photoshop or Pixelmator, or some other photo editor and change the mode to RGB. Save it and put it back in the timeline. This should solve your problem.
If you are having problem finding out what image in the timeline is causing the problem, just export small bits by changing the in and out points until you get the error and then investigate between the in and out points.