Nokia Siemens 1600 DSL router

Dear Concerned,

Request your help in sorting out my issue with Nokia Siemens 1600 DSL router configured for Airtel.

My laptop & my blackberry phone dosent recognize the Wifi router always,in order to get the Wifi on my Laptop & on my Blackberry i have to keep on refreshing the refresh button to discover my wifi network.
And some time i have to switch on & off the modem several times to get the connection.
This dosent happen always some time the wifi network gets connected automatically as soon i switch on the router, but some time it dosent recognise my laptop & mobile .

I would appreciate if any one can help me getting this sorted.

Thanks in advance