[SOLVED]Product page show product "out of stock"

Hi,
I have an ecommerce site running on joomla1,7 and hikashop 1.5.6 standard
the system worked fine until yesterday.

today I tried to add a product with 3 variants tables as all product in the site
when I show the product it appear as "no stock"

amount product set is unlimited

you can look an example at this link

www.avaiashop.it/component/hikashop/prod...ay-2.html?Itemid=124

all other products previously added are working fine
please help me

Scenario:
quantity of main product=-1
quantity for each variant set=-1
min quantity order=0
max quantity order=unlimited

when the products are showed without any variant they work fine
when I add one only variant, product page show the product "out of stock"
and is'nt possible add it to chart

The product previously added continue to working fine
So at the moment I can't add any product to my site, 'cause is'nt possible for the customers order it

please help me!!!!

I checked in "manage variants", the quantity is correctly set, but all recently added product are set as "unpublished" in "manage variants" panel, I just published the variants and the system work fine

Thanks you so much