no automatic reauthentication/reconnect
 

We use a Cisco 350 PCMCIA for network communication on cranes.

The cranes sometimes lose the network contact to the access point
while driving or staying in bad points of a hall, because of a too
weak signal and/or signal overlays. This happens about one or two
times per week.
If the interruption lasts longer than 5 seconds, the network
connection in the systray is deactivated.

When the signal is back in a sufficient strength, there is still no
connection to the network (Systryicon is disabled; ping does not
work). Only if you click in the Aironet Client Monitor on
reauthenticate, the connection is up again.

I tried already:
WindowsXP-KB826942 (Windows XP-Supportpatch für Wireless Protected
Access)
and Q239924 („disable Media Sense for TCP/IP in Windows")

SP2 seems to solve the problem, but at the moment it is not possible
to install ServicePack 2 because of IT Guidelines in the Enterprise.

Is there a MS Fix I didn't find ?
Is there a possibility to extend the Timeout of 5 seconds ?
Can we automate the reauthentication process?


Details:
Windows XP SP1
current driver version of the Cisco Card

Network Security Settings:
Network Authentication - NONE
DATA Encryption – Static WEP Key
ACCESS POINT Authentication - OPEN


Greetings,

Lars