I have a Joomla 1.5.26 site and I have K2 extension installed

I have installed JOOMSEF 3 with K2 ARTIO extension.

The URL Rewrite is OK for non K2 articles, but with all K2 article (courses in many cities) when I click on the first city is ok. When I click on the second, third, etc, the URL remain ever on the first city.

I have done some CUSTOM URL in manage SEF URL writing the original URL (index.php?Itemid=2048&option=com_k2&view=itemlist&layou etc....) and the SEF URL I need.

But nothing. When I click on the first city, OK, when I click on the second, third, etc.... the URL remain ever on the firts city.
What can I do?