I came across this problem two days ago---I would've posted a bug report, but I've got around a zillion homework sets to grade...so it slipped off my radar screen.
In users-bulk-upload-2.tcl (found in packages/dotlrn/www/admin) change the line
set user_id [ad_user_new $row(email) $row(first_names) $row(last_name) $password "" "" "" "t" "approved"]
to read
set user_id [ad_user_new $row(email) $row(first_names) $row(last_name) $password "" "" "" "t" "approved" "" $row(id)]
Matt