[ gpsdrive ] Errors with gdal_warp

[R. G. Newbury]

I'm trying to transform NOAA RNC charts to tif's (and then use Hamish' 
gdalslice to make tiles). BUT, I get errors with gdalwarp:

[root at tor4 11466]# gdalwarp -t_srs "EPSG:4326" -orde
r 2 -rn -co 'COMPRESS=DEFLATE' 11466_1.KAP 11466_1.t
if
Copying color table from 11466_1.KAP to new file.
Creating output file that is 9318P x 11913L.
Processing input file 11466_1.KAP.
:0...10...20...30...40...ERROR 1: ZIPDecode:11466_1.             tif: 
Decoding error at scanline 0, incorrect header              check
ERROR 1: TIFFReadEncodedStrip() failed.

ERROR 1: IReadBlock failed at X offset 0, Y offset 0
ERROR 1: GetBlockRef failed at X block offset 0, Y b             lock 
offset 0

Can anyone suggest a fix? This appears to be an original problem with 
the KAP file, as re-downloading results in the same error.

Geoff