Variables set in the submit handler functions of forms are updated but never created in i18n_variables

The commit "Fixed: Multilingual variables cache being rebuilt every page load, by patrick2000, #905428" (650b3f4c8c04232ab0a9757a27da8f7aff3caaa1 on Thu Sep 9 2010) changed _i18n_variable_exit() so that variables would only be saved if they had a corresponding entry in $i18n_conf:

-    foreach ($i18n_conf[$langcode] as $name => $value) {
-      if (isset($conf[$name]) && $value != $conf[$name]) {
+    foreach (i18n_variable() as $name) {
+      if (isset($conf[$name]) && isset($i18n_conf[$langcode][$name]) && $conf[$name] != $i18n_conf[$langcode][$name]) {

As a result, since version 6.x-1.7 any module that attempts to stores a multilingual variable in their form submit handlers will not have it saved to the i18n_variables table. If a variable was previously saved to the i18n_variables table (for example, while using an older version of the i18n module) then it will be unaffected.

This was discovered while looking into Ubercart issue #834290: Address fields are no longer multilingual variables and cannot be translated.