Re-queue All emails doesn´t work.

Hi, your plugin is great. But I have troubles when I send e-mails, with the Re-quee All Emails.
I set an e-mail, and I send it to one-hundred subscribers from a list, and it works fine. But three hours later when I want to send more e-mails from the send queue I can´t.
In order to continue sending e-mails, I have to click in the Requeue button of each e-mail from that queue, because the
“Re-queue All emails” doesn´t work when I press it.

So, to sum up, I have to send the e-mails one by one, press Re-queue one hundred times, and it´s very annoying.
Is there any reason why the button Re-queue All Emails doesn´t work?
Thanks a lot,
Regards

http://wordpress.org/plugins/sendpress/