Theoretically, it means the drive cannot find a laser power setting that gives an acceptable result - eg. a media problem, or a drive fault.
What should happen, is that the drive will use (in order):
1. The ATIP code, and any information stored in the firmware about the media.
2. If the drive doesn't "know" the media, it will take the basic calibration from the code - for the lowest qulaity media, this can actually be WRONG.
3. It then uses the power calibration area (PCA) to test with tha laser power at several steps above and below the indicated setting, evaluating the result and selecting the best or middle of the band - or reporting an error if it cannot get an acceptable result.
Practically, it seems to be an error which can be thrown for other reasons as well.
Is it a new drive, an old drive?
Media you've used before, media you've never tried before, old media that may have been badly stored.