tablet and phone connection problem

[#1]

both my laptop and desktop pc stay connected to my router no problems at all but my old iphone 3 and my new galaxy never conected properly  and my new kinlde fire hd keeps losing conection with an authentication faliure being the message, if i restart the router it reconncts for a while before disconecting again.
any solutions plz.

[#2]

which router is it? if it's a pn supplied one it may require a firmware update.

[#3]

its a plussnet supplied white thompson one. cant see a model number
adie:quote

[#4]

ive just checked and the firmware is up to date, ps whats the button on the front of the router for?

[#5]

The button toggles the wireless off and on, though I think it needs to be held for a few seconds to do that.

[#6]

Hi biggyjaay,
Are your desktop and laptop connected wired or wireless?

[#7]

wireless

[#8]

Hi biggyjay,
Are both the iPhone and Kindle up to date as well? Also do you see any error messages when the connection drops (rather than when the phone/kindle try to reconnect) at all?