Problem with 3com kit

[petermeachem]

A customer has a 3com adsl/router/firewall/wireless box (3CRWE754G72-A) here

http://www.3com.com/products/en_US/detail.jsp?tab=features&pathtype=purchase&sku=3CRWE754G72-A

and two 3CRSHEW696 usb client boxes

http://www.3com.com/products/en_US/detail.jsp?tab=features&pathtype=purchase&sku=3CRSHEW696.

They are getting very poor connectivity. They seemed to be ok with just one client kit installed, but couldn't connect at all with two in. I upgraded the router firmware to 1.24 and ran the beta software ( the 3com bloke said it ws ok!) here

http://www.3com.com/products/en_US/result.jsp?selected=5&sort=effdt&sku=3CRSHEW696&order=desc

The activity lights on the client devices blink away like mad, lots of dropped packets and the wireless signal is very good.
Both pc's are running xp.
This should work ok shouldn't it? Any idea what is wrong. I'm supposed to go and fix it tomorrow and haven't a clue what to do.

http://www.accuflight.com

http://www.lettersdirect.co.uk

http://www.ourhouseinportugal.co.uk/