Σ Time Spent does not reflect the total time spent by issue and sub-tasks in HTML filter mail subscriptions

If you configure your issue navigator to include the 'Σ Time Spent' field and subscribe for filter notifications having HTML in the user preferences, the 'Σ Time Spent' is mailed with the 'Time Spent' value, instead of the total time spent for the task and its subtasks. So, the value in the mail subscription is different to the one shown in the filter.

Please see attachments.