kasp_auditor question

Using svn revision 1855 the following is seen when trying to run the auditor:

[root@uks-dnssign-01 auditor]# kasp_auditor --conf /etc/opendnssec/conf.xml
/usr/local/lib/opendnssec/kasp_auditor/preparser.rb:140:in `normalise_line': undefined method `strip' for nil:NilClass (NoMethodError)
from /usr/local/lib/opendnssec/kasp_auditor/preparser.rb:96:in `normalise_zone_and_add_prepended_names'
from /usr/local/lib/opendnssec/kasp_auditor/preparser.rb:69:in `foreach'
from /usr/local/lib/opendnssec/kasp_auditor/preparser.rb:69:in `normalise_zone_and_add_prepended_names'
from /usr/local/lib/opendnssec/kasp_auditor/preparser.rb:67:in `open'
from /usr/local/lib/opendnssec/kasp_auditor/preparser.rb:67:in `normalise_zone_and_add_prepended_names'
from /usr/local/lib/opendnssec/kasp_auditor.rb:178:in `normalise_and_sort'
from /usr/local/lib/opendnssec/kasp_auditor.rb:177:in `fork'
from /usr/local/lib/opendnssec/kasp_auditor.rb:177:in `normalise_and_sort'
from /usr/local/lib/opendnssec/kasp_auditor.rb:133:in `run_with_syslog'
from /usr/local/lib/opendnssec/kasp_auditor.rb:115:in `each'
from /usr/local/lib/opendnssec/kasp_auditor.rb:115:in `run_with_syslog'
from /usr/local/lib/opendnssec/kasp_auditor.rb:81:in `run'
from /usr/local/lib/opendnssec/kasp_auditor.rb:79:in `open'
from /usr/local/lib/opendnssec/kasp_auditor.rb:79:in `run'
from /usr/local/bin/kasp_auditor:110
Sep 23 10:52:13 localhost kasp_auditor[25699]: Error sorting files (/var/opendnssec/unsigned/coop and /var/opendnssec/signed/coop) : ERR 256- moving on to next zone
Auditor found errors - check log for details