can't display some variations

hi, i’m in love with this plug in and I will buy the pro version but why sometimes some variations doesn’t display? I’ve tried to refresh but it doesn’t work, every time I must to create a brand new product with the same variations and after this i will display the new product but the oldest doesn’t display any variation.

http://ww.wp.xz.cn/plugins/smart-manager-for-wp-e-commerce/