You may be able to resolve the issue by changing your Efficient Networks Speedstream 5200 ADSL modem from Router Mode to Bridge
Mode (if applicable).

If that fails to resolve the issue or you definetly need the Router functionality of the Efficient Networks Speedstream 5200. Please read the information below that was passed onto us from an iCu2 User:

"I found a firmware update thanks to google on a Brazilian website (http://www.abusar.org/manuais/5200/).

My router was using the first one listed there. Im using now E240_A29_69-24_4080_69-25_v1 and it works fine on iCu2.

My connection didnt freezed after some mins on iCu2 and router is perfect on the other pcs of the LAN"