pfSense

I have an alix (alix3d2, 2xminiPCI, 1xLAN, 2xUSB, bios 0.99h) board
with 2 miniPCI WiFi cards on it (WLM54GP23, Atheros AR2413/AR2414 200mW).

One WiFi card is used as WAN interface in Infrastructure mode and spoofed
MAC address and the other is configured as Access Point.

As soon as the WAN IP type is switched to PPPOE kernel panic occurs (process
mpd5).

Output on serial console:
------------------------------------------------------------------------
Configuring WAN interface...ifconfig: interface pppoe1_wlan0 does not exist
starting pppoe1 link...

Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address = 0x0
fault code = supervisor read, page not present
instruction pointer = 0x20:0xc05bc255
stack pointer = 0x28:0xe3a0478c
frame pointer = 0x28:0xe3a04850
code segment = base 0x0, limit 0xfffff, type 0x1b = DPL 0, pres 1, def32 1, gran 1
processor eflags = interrupt enabled, resume, IOPL = 0
current process = 11159 (mpd5)
trap number = 12
panic: page fault
cpuid = 0
Uptime: 32s
Cannot dump. Device not defined or unavailable.
Automatic reboot in 15 seconds - press a key on the console to abort
Rebooting...
PC Engines ALIX.3 v0.99h
640 KB Base Memory
261120 KB Extended Memory
------------------------------------------------------------------------

Board is runnig pfSense 1.2.3 (7.2-RELEASE-p5 FreeBSD 7.2-RELEASE-p5) since
3 years without any issue. Kernel panic occurs on latest snapshot 2.1
(from 21.02.2013)

Any hints ?