Problems with AP-2500 freezing

Hi

We have a wireless setup at home containing the following 'steps':
(The Traffic Shaper is between the subscribere and base)

Internet subscriber line (2,3 MBit SDSL)
-> Netscreen XT5 (firewall)
-> Orinoco base (11mbit LAN, bridging enabled)
--------------NEW LOCATION--------------------------------
-> Orinoco subscriber (11mbit LAN, bridging enabled)
<- Traffic Shaper (11mbit LAN, bridging enabled)
-> Orinoco base (11mbit LAN, bridging enabled)
--------------NEW LOCATION--------------------------------
-> Orinoco subscriber (11mbit LAN, bridging enabled)
-> Orinoco AP-2500 as base (2mbit LAN, bridging enabled)
-> Clients connected to the AP-2500 (approx 30)

Now we have blocked most of the port ranges that contain garbage
(spam, dos) and all icmp incoming requests with the netscreen.

The problem is this:
After a while (ranging from 2-5 hours uptime) when traffic is at its
most the AP-2500 stops responding, its running with 2 green lights but
shows no activity. This also requires us to manually boot the AP-2500.
Everytime this happends i have checked the netscreen and found alot
(100-200+) incidents of outgoing and incoming data at the same
hh:mm:ss.

What boggles my mind is why all the other bases/subscribers does not
freeze.

So I am wondering the following:
1) Could the AP-2500 freeze if the datarate is limited (note: limited)
to 2mbit/s and the internet line is running at 2,3 mbits. I mean this
should not make it freeze because of overloading trying to send too
many packets?

2) Could this be a software/firmware issue?

3) The AP-2500 freezes/overloads if its getting too many requests at
once? (not taking its limit into consideration).

If anybody is using/having used the AP-2000 or AP-2500 and experienced
any simular case i would be gratefull for a response to either this
thread or (E-Mail Removed)

Note that there is no firewall connected between the clients and the
AP-2500 so we cant protect the AP-2500 from trusted spam/DoSS.

Thanks
Marius