Forum .LRN Q&A: Forums + Attachments in dotlrn 2.0 broken

I just tried dotlrn 2.0.0b4 which includes openacs 5.0b4.  I tried setting a URL as an attachment to a forum posting, and I get the error below.  I had a quick look in the file storage package for fs::simple_get_type_pretty_name, and could not find it.  Any suggestions on how to resolve this?

Thanks,
Nick.

invalid command name "fs::simple_get_type_pretty_name"
    while executing
"fs::simple_get_type_pretty_name -type $type"
    invoked from within
"set pretty_name [fs::simple_get_type_pretty_name -type $type]"
    ("uplevel" body line 34)
    invoked from within
"uplevel {
          ad_page_contract {
    page to add a new nonversioned object to the system

    @author Ben Adida (mailto:ben@openforce.net)
    @author..."
    (procedure "code::tcl::/Users/spauser/web/spa/packages/attachments/www/s..." line 2)
    invoked from within
"code::tcl::$__adp_stub"
    invoked from within
"if { [file exists $__adp_stub.tcl] } {

      # ensure that data source preparation procedure exists and is up-to-date
      adp_init tcl $__adp_stub
..."
    ("uplevel" body line 3)
    invoked from within
"uplevel {

    if { [file exists $__adp_stub.tcl] } {

      # ensure that data source preparation procedure exists and is up-to-date
      adp_init t..."
    (procedure "adp_prepare" line 2)
    invoked from within
"adp_prepare "
    (procedure "template::adp_parse" line 30)
    invoked from within
"template::adp_parse [file root [ad_conn file]] {}"
    (procedure "adp_parse_ad_conn_file" line 7)
    invoked from within
"$handler"
    ("uplevel" body line 2)
    invoked from within
"uplevel $code"
    invoked from within
"ad_try {
                $handler
            } ad_script_abort val {
                # do nothing
            }"
    invoked from within
"rp_serve_concrete_file [ad_conn file]"
    (procedure "rp_serve_abstract_file" line 60)
    invoked from within
"rp_serve_abstract_file "$root/$path""
    ("uplevel" body line 2)
    invoked from within
"uplevel $code"
    invoked from within
"ad_try {
    rp_serve_abstract_file "$root/$path"
    set tcl_url2file([ad_conn url]) [ad_conn file]
    set tcl_url2path_info([ad_conn url]) [ad_conn path_inf..."

Anyway, I can now attach URLs to forum postings.

Anybody know why the fs-simple-procs files were left out of OpenACS 5.0.0?