Not a biggy - more of a "nice to have". I have got past this issue myself, but this IR may help the next person!
When using the CGI output, if the script fielding the output returns anything but OK the CGI output script complains that it has received an unexpected response. Fair enough.
What would be helpful would be if it could echo back what the unexpected response actually was.
This would help folks debug their "other end" scripts - the response will very likely contain line numbers and other helpful stuff.