Semantic Fields broken when using locale

Just activated the module.
Impossible to add preset or editing existing one: below is the error message displayed (hundreds of lines truncated in its middle):

PDOException : SQLSTATE[22001]: String data, right truncated: 1406 Data too long for column 'source' at row 1: INSERT INTO {locales_source} (location, version, source, context, textgroup) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4); Array ( [:db_insert_placeholder_0] => /admin/structure/semantic_fields/list/clear/edit [:db_insert_placeholder_1] => 7.26 [:db_insert_placeholder_2] => You could use tokens, like <em>[node:title]</em> and <em>[node:url]</em><table class="token-tree sticky-enabled"> <caption></caption> <thead><tr><th>Nom</th><th>Jeton (token)</th><th>Description</th> </tr></thead> <tbody> <tr id="token-random" class="token-group odd">
............ [truncated] ...............
<td>Premier</td><td class="token-key">[array:first]</td><td>Le premier élément du tableau.</td> </tr> <tr id="token-array--value" class="child-of-token-array even"><td>Valeur</td><td class="token-key">[array:value:?]</td><td>La valeur spécifique de la liste.</td> </tr> </tbody> </table> [:db_insert_placeholder_3] => [:db_insert_placeholder_4] => default ) dans locale() (ligne 749 dans /var/aegir/platforms/pack_cms_v2.00/modules/locale/locale.module).

Environment:

• Drupal 7.26
• PHP 5.3.10-1ubuntu3.10
• Apache/2.2.22 (Ubuntu)
• MySQL 5.5.35-0ubuntu0.12.04.2