When i copy the item's link from my site (www.lasithisport.gr) to my facebook profile then i see that the item title does not appeard. In the title's position appeard the name of item's category. Please check the attachment and you will understand what i mean. Sorry for my bad English

Hi. You have some extra open graph tags in your page. K2 is generating the correct ones but in your page there are some extra ( actually they are duplicates making things even worse). K2 is not related with that. It's up to you to find where the extra incorrect tags are coming from.

i saw that in facebook debugger (facebook developers). But i do not know where i must search to fix it...

Since you are the owner ( and developer ? ) of the site you are supposed to know better than me. The extra tags are not coming from K2 for sure. Try to disable some plugins until you find the one that is doing this. It might also coming from your template.

i was checking the plugins but nothing happen. ok thank you for your responce have a nice day...

You are welcome. If it's not a plugin, then it might be hardcoded in your template.