Magento: After ordering configurable product, its

my problem is: i have a product with simple products as childs. (maybe tshirts whith size S-XL and some colors) Now if i order one of this, it is canceled with the order-confirmation email.

I think its a problem with the stock but i dont know. There are 99 items in stock of every kind and all are activated and ready to deliver.

Anybody who has had the same problem?

Here the Solution:

The problem was crossing ids in the order tables so magento mixed up all items.

Solved this with truncating all order tables:

TRUNCATE sales_order; TRUNCATE sales_order_datetime; TRUNCATE sales_order_decimal; TRUNCATE sales_order_entity; TRUNCATE sales_order_entity_datetime; TRUNCATE sales_order_entity_decimal; TRUNCATE sales_order_entity_int; TRUNCATE sales_order_entity_text; TRUNCATE sales_order_entity_varchar; TRUNCATE sales_order_int; TRUNCATE sales_order_text; TRUNCATE sales_order_tax; TRUNCATE sales_order_varchar; TRUNCATE sendfriend_log; TRUNCATE tag; TRUNCATE tag_relation; TRUNCATE tag_summary; TRUNCATE wishlist; TRUNCATE log_quote; TRUNCATE report_event;

TRUNCATE sales_flat_quote; TRUNCATE sales_flat_quote_address; TRUNCATE sales_flat_quote_address_item; TRUNCATE sales_flat_quote_item; TRUNCATE sales_flat_quote_item_option; TRUNCATE sales_flat_quote_payment; TRUNCATE sales_flat_quote_shipping_rate; TRUNCATE sales_flat_order_item;

ALTER TABLE sales_order AUTO_INCREMENT=1; ALTER TABLE sales_order_datetime AUTO_INCREMENT=1; ALTER TABLE sales_order_decimal AUTO_INCREMENT=1; ALTER TABLE sales_order_entity AUTO_INCREMENT=1; ALTER TABLE sales_order_entity_datetime AUTO_INCREMENT=1; ALTER TABLE sales_order_entity_decimal AUTO_INCREMENT=1; ALTER TABLE sales_order_entity_int AUTO_INCREMENT=1; ALTER TABLE sales_order_entity_text AUTO_INCREMENT=1; ALTER TABLE sales_order_entity_varchar AUTO_INCREMENT=1; ALTER TABLE sales_order_int AUTO_INCREMENT=1; ALTER TABLE sales_order_text AUTO_INCREMENT=1; ALTER TABLE sales_order_tax AUTO_INCREMENT=1; ALTER TABLE sales_order_varchar AUTO_INCREMENT=1; ALTER TABLE sendfriend_log AUTO_INCREMENT=1; ALTER TABLE tag AUTO_INCREMENT=1; ALTER TABLE tag_relation AUTO_INCREMENT=1; ALTER TABLE tag_summary AUTO_INCREMENT=1; ALTER TABLE wishlist AUTO_INCREMENT=1; ALTER TABLE log_quote AUTO_INCREMENT=1; ALTER TABLE report_event AUTO_INCREMENT=1;

ALTER TABLE sales_flat_quote AUTO_INCREMENT=1; ALTER TABLE sales_flat_quote_address AUTO_INCREMENT=1; ALTER TABLE sales_flat_quote_address_item AUTO_INCREMENT=1; ALTER TABLE sales_flat_quote_item AUTO_INCREMENT=1; ALTER TABLE sales_flat_quote_item_option AUTO_INCREMENT=1; ALTER TABLE sales_flat_quote_payment AUTO_INCREMENT=1; ALTER TABLE sales_flat_quote_shipping_rate AUTO_INCREMENT=1; ALTER TABLE sales_flat_order_item AUTO_INCREMENT=1;