I have a generic Android tablet which I set up on our Belkin-N-ADSL-81C7DD 3 days ago, it was working fine until yesterday when suddenly it spends all it's time saying "Obtaining IP Address", my cellphone is now doing exactly the same thing (also Android, an LG P500).    My printer took quite a while to connect to the network last night as well.   Nothing has changed on it at all.  When things are trying to connect the modem has the orange flashing light for wireless showing it's trying at least, but obviously something's not right.
It's still working for the laptop (Acer Aspire).
I've tried unplugging the modem for a few minutes and that made no difference.   What else can I do?