Yes, The rear speaker is the same as the i730s. Do you have insurance on your plan? If so, just take the phone to your a Nextel store (not a indirect dealer) and have the phone replaced.
i have a 710. i've noticed that the speakers have a lower quality sound on the 700 series and the phones with the speakers on the back. phones like the i90 and i95 sound alot better. anyone else notice too?