DB_DataObject Oddity with LIMIT

With this construction I get the following query:

        DB_DataObject::debugLevel(5);
        $sql1 = DB_DataObject::factory(TBL_SMS_CENTER_KEYWORDS);
        $sql2 = DB_DataObject::factory(TBL_SMS_CENTER_SERVICES);
        $sql3 = DB_DataObject::factory(TBL_SMS_CENTER_ACCOUNTS);

        $sql2->uk_default = $xml->AccountID;
        $sql1->keyword_id = $xml->KeywordID;

        $sql1->limit(0,5);

        $sql2->joinAdd($sql3);
        $sql1->joinAdd($sql2);

        $total = $sql1->find();

As you can see no LIMIT is displaying on the debug report.

    DO_Sms_keywords: QUERY: SELECT *
    FROM sms_keywords
    INNER JOIN admin.sms_services ON admin.sms_services.service_id=sms_keywords.service_id
    INNER JOIN admin.sms_accounts ON admin.sms_accounts.account_id=sms_services.uk_default
    WHERE ( admin.sms_services.uk_default = 0 ) AND ( sms_keywords.keyword_id = 186 )

When I set debug to 5 I get this query which shows the limit. Only a small thing but took me 15 mins to try and find out why LIMIT wasnt be initialised only to find out it is probably a debug issue.

    "last_query";s:311:"SELECT *
    FROM sms_keywords
    INNER JOIN admin.sms_services ON admin.sms_services.service_id=sms_keywords.service_id
    INNER JOIN admin.sms_accounts ON admin.sms_accounts.account_id=sms_services.uk_default
   WHERE ( admin.sms_services.uk_default = 0 ) AND ( sms_keywords.keyword_id = 186 ) LIMIT 0, 5"