net6501-70: Corrupt LAN NVM configuration after 1.41c BIOS upgrade

Hello -
I read about the poor performance of the net6501 with the stock 1.41a BIOS so I upgraded it to 1.41c.  After rebooting, I now get this error during the POST:

PXE-E05: The LAN adapter's NVM configuration is corrupted or has not been
initialized. The Boot Agent cannot continue.

If I continue and allow FreeBSD 10.1p9 to boot I get these kernel messages on startup, and the em* interfaces go missing:

em0: <Intel(R) PRO/1000 Network Connection 7.4.2> port 0x2000-0x201f mem 0xa1000000-0xa101ffff,0xa1020000-0xa1023fff irq 19 at device 0.0 on pci5
em0: Using MSIX interrupts with 3 vectors
em0: The EEPROM Checksum Is Not Valid
device_attach: em0 attach returned 5

How do I recover from this?  Is there some way to reflash the NIC's BIOS??

Thanks.

- Max