pfSense

Setup:
- 4G WiFi modem / 802.11g/n Channel 2 / WPA2 Personal / AES Encryption

pfsense: 2.2.4

Dell Lattitude D630
   WAN: Intel(R) Wireless WiFi Link 4965 
   LAN: Broadcom Gigabit Ethernet Controller

Background:
this laptop has been running my home firewall for over 4 years on 2.1.x (up to 2.1.3)
The setup has varied at times (different houses).

This recent house move, I have been using it with a WiFi 4G modem. the pfsense WAN link is Wifi with the Access point and Password set in the WAN config.
It works well.

The attempted upgrade (wanted a working squid proxy) to 2.2.4 came with a consistent kernel crash.

What I have observed:

on 2.1.5:

The WAN WiFI link is - AES, 802.11g, WPA2 Personal, Channel 2 between pfsense and the 4G Wifi modem.

on 2.2.4:

The WAN Wifi link "attempted" was 802.11n, AES, WPA2 Personal : Crashes Kernel as soon as the link attempts to DHCP.
The premises I am in, has a "public" subscription WiFi. When pfsense is first setup, the WAN link connects to this public WiFi link, as their is no encrypted password, it works. (Tomizone@BellaVista)
When I change the SSID to mine, ("traady-9 - see attached") with WPA2 encryption, the kernel crashes and the machine reboots.

on 2.1.5:

The WAN WiFi link works on either TomiZone (public, no encryption) or mine, (AES, WPA2)

Attached are some debug details of the two wifi access points described above.

As I have to work (use the internet), I have not gone back to testing 2.2.4 to assess what the cause is.
If someone wants to provide some steps for extra info they may require I am happy to do the leg work and work out what the cause is.

---- extra info ----

The same crash occured with a Lenovo X420, same setup - WAN wifi to "traady-9" interface.