Here are some indexes that should exist but don't that cause joins without indexes problems:
Code:
CREATE INDEX offers_offer_name_idx USING BTREE(offer_name) ON xcart_offers
CREATE INDEX offers_offer_idx USING BTREE(offerid, offer_avail) ON xcart_offers
CREATE INDEX offers_offer_dates USING BTREE(offer_start, offer_end) ON xcart_offers
CREATE INDEX offer_bonus_params_idx USING BTREE(bonusid,param_id,param_type) ON xcart_offer_bonus_params
CREATE INDEX ccprocessors_processor_idx USING BTREE(processor, use_preauth, has_preauth) ON xcart_ccprocessors
CREATE INDEX ccprocessors_paymentid USING BTREE(paymentid) ON xcart_ccprocessors