I tried using zsync (on raring) for the first time to download the raring image today but it's not working. Have others seen this? When was the last time zsync worked?

Code:
zsync http://cdimage.ubuntu.com/daily-live/current/raring-desktop-i386.iso.zsync
#################### 100.0% 306.6 kBps DONE     

reading seed file raring-desktop-i386.iso.part: ******************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************Read raring-desktop-i386.iso.part. Target 51.3% complete.      ******************************************
downloading from http://cdimage.ubuntu.com/daily-live/current/raring-desktop-i386.iso:
##########---------- 51.3%
zsync received a data response (code 200) but this is not a partial content response
zsync can only work with servers that support returning partial content from files. The person/entity creating this .zsync has tried to use a server that is not returning partial content. zsync cannot be used with this server.
See http://zsync.moria.orc.uk/server-issues
##########---------- 51.3% 0.0 kBps aborted    

failed to retrieve from raring-desktop-i386.iso
Aborting, download available in raring-desktop-i386.iso.part
verifying download...