Here's the DAV section from my nsd.tcl. I made sure that /tmp/openacs-5/data and all subdirectories existed and had 777 perms.
#---------------------------------------------------------------------
#
# WebDAV Support (optional, requires oacs-dav package to be installed
#
#---------------------------------------------------------------------
ns_section ns/server/${server}/tdav
ns_param propdir /tmp/${server}/data/dav/properties
ns_param lockdir /tmp/${server}/data/dav/locks
ns_section ns/server/${server}/tdav/shares
ns_param share1 "OpenACS"
#ns_param share2 "Share 2 description"
ns_section ns/server/${server}/tdav/share/share1
ns_param uri "/*"
# all WebDAV options
ns_param options "OPTIONS COPY GET PUT MOVE DELETE HEAD MKCOL POST PROPFIND PROP
PATCH LOCK UNLOCK"
#ns_section ns/server/${server}/tdav/share/share2
#ns_param uri "/share2/path/*"
# read-only WebDAV options
#ns_param options "OPTIONS COPY GET HEAD MKCOL POST PROPFIND PROPPATCH"
