Non-IP broadcast Cisco Aironet 1200 problem

Hello,

I'm having a problem with relaying broadcast non-IP traffic through
the Cisco Aironet 1200 access point.

The access point uses the default configuration. There is only SSID
defined and no security settings. Additionally the IP address of the
AP point has been changed.

From the host connected to the wired port of the AP I can ping the AP
and associated clients. From the client I can successfully ping AP and
the host connected to the wired interface of the AP. So the ARP
broadcast goes through.
I'm sending different packets to the AP through its wired interface.
Any type of the unicast packet (IP and non-IP) destined (at the
Ethernet level) to the connected client go through the AP. I'm having
a problem with broadcast packets. The only packets, which get to the
client, are IP and ARP broadcasts (interesting thing is that incorrect
ARP headers do not go through).
So I cannot send any broadcast packets not having Ethertype set to
0x0800 or 0x0806. My WLAN clients use some proprietary protocols to
communicate with hosts in the wired network and some of packets are
broadcasted.

Additionally DHCP requests and broadcast DHCP replies do not go
through.

The Aironet 1200 allows defining some filters. In my case this service
is disabled, but I could not find any information if there are some
default filters set. Any way using http interface I cannot define the
filter to forward all the broadcast packets - GUI does not allowed to
add broadcast address - 0xffffffffffff with 48 bits mask.

When I send these non-IP broadcast packets to the wired interface of
the AP - the broadcast counters on the wired interface of the AP do
not get incremented. If the IP broadcast packet is sent, the counter
is incremented.

Could anybody give me some advices?

Thanks in advance,
Kamila