The Linksys SPA9000 5.1.5a firmware may cause phone reboots during calls.
Linksys has replaced the 5.1.5a firmware on their website with a previous firmware release (5.1.1).
Customers who are experiencing phone reboot problems with the 5.1.5a firmware are advised to rollback to the 5.1.1 release.
Linksys released the SPA9000 5.1.5a firmware on December 7th. By December 10th, the Linksys (Sipura) SPA Users Group was receiving reports of SPA941/SPA942 reboots during calls. Linksys responded on December 11th, by rolling back the firmware available on the Linksys website.
We will advise customes when a new SPA9000 firmware release is available.