ご回答ありがとうございます。

>同様のデータを管理機能で入力して、バックアップファイルを作成して確認するのがよいかと思います。
phpPgAdminから「dtb_customer」に、すでに登録されている顧客情報を参考にして、直接値を入力してみました。
顧客情報にはもう１人増えたように表示され、その状態でバックアップを取って、リストアを行ってみましたが、エラーが出てダメでした。


それから、苦闘数時間…やっと解決する事ができました（＾ー＾）

◆「buckup_data.csv」の中のdtv_customerの記述部分です
dtb_customer
customer_id,name01,name02,kana01,kana02,zip01,zip02,pref,addr01,addr02,email,email_mobile,tel01,tel02,tel03,fax01,fax02,fax03,sex,job,birth,password,reminder,reminder_answer,secret_key,first_buy_date,last_buy_date,buy_times,buy_total,point,note,status,create_date,update_date,del_flg,cell01,cell02,cell03,mobile_phone_id,mailmaga_flg
"1","てすと0","です","テスト","デス","001","0011","1","あああ","いいい","test1@mail.hoge.ne.jp";,"","012","345","6789","","","","1","","","66401699cac640c70e0a76327c990e53f5d2896f","2","test0","r48e49bcbd6903EU72ehdt","","","0","0","","","2","2008-10-02 05:00:43.930652","2008-10-02 05:00:43.930652","0","","","","","2"
"2","てすと2","です","テスト","デス","001","0011","1","ううう","えええ","test2@mail.hoge.ne.jp";,"","234","567","8900","","","","1","","","071805b8ca1f5250a01b1df3c859a255ac058a2c","2","test2","r48e49c3b5ce9bRxbqDQDV","","","0","0","","","2","2008-10-02 05:02:35.433828","2008-10-02 05:02:35.433828","0","","","","","2"
"3","てすと3","です","テスト","デス","001","0011","1","ううう","えええ","test3@mail.hoge.ne.jp";,"","234","567","8900","","","","1","","","071805b8ca1f5250a01b1df3c859a255ac058a2c","2","test2","r48e49c3b5ce9bRxbqDQDV","","","0","0","","","2","2008-10-02 05:02:35.433828","2008-10-02 05:02:35.433828","0","","","","","2"

上記の場合、エラーが発生してしまうのですが、原因は「secret_key」にありました。
同じsecret_keyが重複してしまっていたために、エラーが発生していました。
具体的に言うと、例えば下記のデータの場合。

"2","てすと2","です","テスト","デス","001","0011","1","ううう","えええ","test2@mail.hoge.ne.jp";,"","234","567","8900","","","","1","","","071805b8ca1f5250a01b1df3c859a255ac058a2c","2","test2","r48e49c3b5ce9bRxbqDQDV","","","0","0","","","2","2008-10-02 05:02:35.433828","2008-10-02 05:02:35.433828","0","","","","","2"
"3","てすと3","です","テスト","デス","001","0011","1","ううう","えええ","test3@mail.hoge.ne.jp";,"","234","567","8900","","","","1","","","071805b8ca1f5250a01b1df3c859a255ac058a2c","2","test2","r48e49c3b5ce9bRxbqDQDV","","","0","0","","","2","2008-10-02 05:02:35.433828","2008-10-02 05:02:35.433828","0","","","","","2"

２つの顧客情報ともに、「secret_key」が「r48e49c3b5ce9bRxbqDQDV」となり重複していたからダメでした。
これを「1」「2」と適当な文字列にして重複しないようにしたら、エラーも出る事無く登録する事ができるようになりました。

ここ数日間、かなり苦戦しましたが、とりあえずできて良かったです。
今後も、私のように顧客情報を一括登録したいと思う方の参考になればと思います。


あと「secret_key」以外に注意しなければならないのは、「autoinc_data.csv」の中に記載されている「dtb_customer,customer_id,*」と言う項目。
「*」には顧客人数の数字が入ります。
５０人を登録したら、「dtb_customer,customer_id,50」となります。
また５０人しか登録していないのに、「dtb_customer,customer_id,100」としたら、次に登録した顧客のIDは101になります。
「*」の数字は、すでに登録している顧客人数以上の数字にするようにして下さい。


私の苦労が、他の方のお役に立てれば幸いです。