m.dem.extract error?

[H. Thomas Foster, II]

I am trying to extract a dem.   I assume i should be using m.dem.extract. 
m.dem.examine will recognize it as will m.dem.extract.  However, when I give
it all the necessary info it exits with the folowing error:
ERROR:  could not find data in correct file.
what am i doing wrong?   the Reference Manual says somthing about getting a
similar error if the C record is 0 and indeed m.dem.extract says that C
record: 0.  the manual says that the format could be wrong and to fast
forward to the next file on the tape.   I am not extracting from a tape so I
don't know what to do.  Does this mean that I can't extract this dem?
thanks for any information




Thomas Foster                                 email: htf1 at psu.edu
Pennsylvania State University            voice: 814-865-1231
Department of Anthropology             fax:  814-863-1474  
409 Carpenter Bldg.
University Park, PA 16802