SBAS on EM-406?

Does the EM-406 support SBAS?

Everything I can find says it supports WAAS/ENGOS, but I haven’t been able to turn it on. I’m getting about 40m of random drift inside. The SiRF II board I have picks up a SBAS sattelite, but it still has more than 60m drift. I have tried turning it on with SiRFDemo, but it keeps reverting back to “testing” mode instead of “integrity”.

If it isn’t supported with the firmware on my module (GSW3.1.1TO_3.1.00.07-C23P1.00), is there a way to upgrade the module? even if I have to send it in?