Mismatch: X:1808 doesn't match requested X:1
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-20889-Book18.ps) >>/Users/jc/w/tmp/Tune-20889-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/SCD/Book18.abc

Error exit status 256; here are some files to check:
[P=get.cgi V=1/1 B=0 scale=0.60 512x512 PNG]
filesizedescription
Tune-20889-Book18.abc 775 ABC music file with the extracted tune(s)
Tune-20889-Book18.ps 39622 PostScript
Tune-20889-Book18.txt 775 Plain-text file with the extracted tune(s)
Tune-20889-get.log 18118 Log file, useful mostly for debugging
These files should be available for 24 hours.