No limited time offer or wrong time

I do not get this module to work properly.
Sometimes there is nothing coming up in my product, and when I check the setting is the module-style back to "no limited time offer"
Sometime when I edit my node, I put "LTO Display time of experation" with regardless of date, I get "Expired:
41 år (year) 19 uker (weeks) 1 dag (day) ago, and if I edit it, I get the error message: user warning: Duplicate entry '31 'for key 1 query: INSERT INTO shop1_uc_lto (nid, expiration, type) VALUES ('31 ', '1305281460', '3 ') in / home / xxxxxx / public_html / xxxxxxx / shop / sites / all / modules / uc_lto / uc_lto.module on line 97. To remove this, I delete the node and then create a new product.

How can I fix this.