Wrong homonym used:

another report: https://drupal.org/node/1823678 which was closed as a duplicate.

confirmed that the typo is used in -dev

  $form['finalize']['enable'] = array(
    '#type' => 'checkbox',
    '#title' => t('Enabled'),
    '#description' => t('Decide wether or not this theme should be enabled.'),
    '#default_value' => $subtheme->status,
    '#access' => $subtheme->automated,
  );

from the above:

    '#description' => t('Decide wether or not this theme should be enabled.'),

should be

    '#description' => t('Decide whether or not this theme should be enabled.'),

here's an attempt at a patch file.

comparing with other .patch files in the queue looks like mine wasn't produced properly. here's another attempt

Just realized that there are multiple misspelling of whether as wether in multiple files.

2 in omega_tools.admin.inc
1 in omega_tools.wizard.inc (reported by nicxvan)

I'll try my hand at another patch in which all of the misspellings will be corrected.

Applied against the 7.x-3.x branch in the git repo. All instances of "wether" changed to "whether." Here's the patch:

Marking this as a duplicate of #1668788: Corrections for text in admin interface and Drush as it covers this and other typos in the UI. That said, thank you for taking the time to put this together!