Memory exhausted when edit/vocabulary

( ! ) Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 24 bytes) in /home/vaulter/www/localhost/includes/database.mysqli.inc on line 144
Call Stack
# Time Memory Function Location
1 0.0003 106672 {main}( ) ../index.php:0
2 0.1299 14782200 menu_execute_active_handler( ) ../index.php:18
3 0.1344 15270880 call_user_func_array ( ) ../menu.inc:348
4 0.1344 15271256 taxonomy_admin_vocabulary_edit( ) ../menu.inc:0
5 0.1344 15272840 drupal_get_form( ) ../taxonomy.admin.inc:223
6 0.1355 15319096 drupal_prepare_form( ) ../form.inc:105
7 0.1362 15387808 drupal_alter( ) ../form.inc:534
8 0.1365 15394568 call_user_func_array ( ) ../common.inc:2784
9 0.1365 15394688 hs_taxonomy_form_taxonomy_form_vocabulary_alter( ) ../common.inc:0
10 0.1414 16333968 _hs_taxonomy_hierarchical_select_get_depth( ) ../hs_taxonomy.module:67
11 0.1414 16333968 _hs_taxonomy_hierarchical_select_get_tree( ) ../hs_taxonomy.module:762
12 10.3592 268378600 db_fetch_object( ) ../hs_taxonomy.module:682
13 10.3592 268378672 mysqli_fetch_object ( ) ../database.mysqli.inc:144

after disabling all Hier.Select modules - all is fine. I can edit voc.

Thanx.