X:1 not found in http://thesession.org/tunes/734
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-17996-734.ps) >>/Users/jc/w/tmp/Tune-17996-get.log 2>&1" returned status 256
http://thesession.org/tunes/734

Error exit status 256; here are some files to check:
[P=get.cgi V=1/1 B=0 scale=0.60 512x512 PNG]
filesizedescription
Form_17996.log 961 Log file, useful mostly for debugging
Tune-17996-734.abc 0 ABC music file with the extracted tune(s)
Tune-17996-734.ps 6 PostScript
Tune-17996-734.txt 0 Plain-text file with the extracted tune(s)
Tune-17996-get.log 4091 Log file, useful mostly for debugging
These files should be available for 24 hours.