WordPress Multilingual Language Plugin – problem (URGENT)

In my page I have few category and each category are linked one Post. Category is listed in down menu like widget on side bar, and when you choose one option from drop down menu you get post, which is linked with right category.
Now I add plugin WPML and strange things happened.
If I understand correctly for each language I need to create new category (which already exist in my original language) and each this new category connect with new Post, which is my original existing Post but in different languages.
I have create in another language few category and also Post related to each of this new category but when I from my main page switch to some of new language and then from drop down menu select value I get error “Error 404 – Not Found” and I directed on my main language home page.
It’s look like new category for new language don’t have link with Post created for this category.
In other hand, when I from my main language page select something from drop down menu and I get some Post with content inside and when then I press any other language I get correct translate Post.
But this is only half functionality, because what if customer want from my main language page to switch directly to another language and then choose from drop down menu some value he will get 404 errors.
Any suggestion, any help.
Thanks