amazon kindle wont work with my wifi

[#1]

No matter how many times I try to connect to my amazon kindle the wifi is not working since I changed to plusnet.  Ive followed all the steps given but it wont recognise the router.
Its driving me nuts so could someone plese give some advice that WILL get it to work. cheers
I have an amazon kindle version kindle 3.4.1
the bottom of the router says  sagemcom; model ROUTER 2704N plusnet
The kindle is showing the plusnet wifi network name but the password wont work.

[#2]

Couple of things to check.
The router wifi channel is <12
The password is CaSeSensitivE and may C0nTa1ne 0's instead of O's. Check you have it correct.

[#3]

5 years later, I fixed this by connecting with a static IP instead of DHCP as this seems to fail on Kindle devices.