Mail to the followign link for the product support with linksys.
http://linksys.custhelp.com/cgi-bin/linksys.cfg/php/enduser/ask.php?p_icf_3=1
If WEP is required between devices from different manufacturers, configure all such devices to use 40-bit WEP.
The IEEE 802.11b specification defines only 40-bit Wired Equivalent Privacy (WEP).
Cisco and other vendors have independently extended the specification by implementing their own versions of 128-bit WEP, which may not be compatible with each other.