Windows CE and Ethernet

Hello together,

I am using a GEODE processor and an intel 8255xer ethernet device.
If I boot with a connected ethernet cable, everything is working fine.
But if I plug in the cable after booting WinCE, no Ethernet connection will
be found, sometimes if I wait a realy long time after plugin the cable, the
connection can be established.
Ipconfig -renew has no effect.

Thanks for your help
Albert