I too had the same issue which I tried to resolve for two days, in the end I had to buy a new Router.
I used to run on a 7 year old Belkin ADSL Modem Wireless G Router model F5D7632-4 fw:F5D7632-4v3_UK_3.01.20.
Samsung i9300 ROM ICS 4.0.4 standard Orange build was working fine.
When I flashed...