infinity wireless connection issue

a week and a half ago my apple product (Ipad 2, Iphone 4 verison, and apple TV) can no longer join the Inifinity Wireless router. Infinity has not been able to fix this and said i have to check with Apple.

Has anyone else had this issue or no of a change that might have effected this? Everything was working fine for 2.5 months with no issues.

I have reset the router/modem and everything works fine for 2 days and like clock work, we are "unable to join the network 'xxxx'". Every other device (PS3, 2 Windows computers and a wired Xbox360) are not effected.

Thanks for any help.