Well, since it appears you had done everything right to begin with, it must have been some sort of interference from UFOs
...or something.
Although, I just had one more crazy thought (happens frequently at this age!)...did you make any changes to either the boat or the crew before starting the patrol? I seem to recall that doing so gave the basic game "heartburn" and perhaps can also cause problems with GWX and/or SH3 CDR. But, if not, then it's back to the UFO "Conspiracy Theory" again.
Regardless, glad you got it working and I wish you "good hunting".
