Oh, I see. So when the customer goes to "My Account" the field is not showing then?
Try re-uploading the tpl_modules_create_account.php file, make sure it is in the correct template folder.
If that fails, then open the file currently on your server, and make sure that the following code is in there:
Code:
<!-- start extrafield -->
<label class="inputLabel" for="extrafield"><?php echo ENTRY_EXTRAFIELD; ?></label>
<?php echo zen_draw_input_field('extrafield', $account->fields['customers_extrafield'], 'id="extrafield"') . (zen_not_null(ENTRY_EXTRAFIELD_TEXT) ? '<span class="alert">' . ENTRY_EXTRAFIELD_TEXT . '</span>': ''); ?>
<br class="clearBoth" />
<!-- end extrafield -->