in my site I have update DS to the last versione 7.x-2.7 and now theme-hook_suggestions does not works. Drupal is update to the last version, too.

I, via mytheme_preprocess_node() function, insert some hook_suggestions for my node, based on node type and a field value. 

Via devel themer I can see this: 

Candidate template files:
ds-1col--node-article-full.tpl.php < ds-1col--node-article.tpl.php < ds-1col--node-full.tpl.php < ds-1col--node.tpl.php < ds-1col.tpl.php

    theme_hook_suggestions (Array, 9 elements)
    0 (String, 13 characters ) node__article
    1 (String, 11 characters ) node__59325
    2 (String, 31 characters ) ds_1col__node_article_cartoline
    3 (String, 31 characters ) ds_1col__node_article_cartoline
    4 (String, 7 characters ) ds_1col
    5 (String, 13 characters ) ds_1col__node
    6 (String, 18 characters ) ds_1col__node_full
    7 (String, 21 characters ) ds_1col__node_article
    8 (String, 26 characters ) ds_1col__node_article_full

Note that element nr 2 is my suggestion, so my function is correct.
(items 2 and 3 are identical because I have tried to insert the same template function code in a module function code to see if there was some type of problem with my templates). 

Why my file (ds_1col__node_article_cartoline -> ds-1col--node-article-immagini.tpl.php) in my "templates" directory in my theme is not used ? If I write a simple ds-1col.tpl.php in my "templates" directory file this file is used. 

I have tried to change one of my module "weight" from 0 to 2 or from 0 to -1 (ds weight is 1) but without luck.

Where is the problem ? 

Thanks.