Like the title said - within the last few months, both my iPad and iPhone 5 seem to have lost the ability to connect to my MIFI 5510L. Both devices ARE able to connect to the Internet through my home network, but with the MIFI, they seem to accept the password (which I have re-entered and checked multiple times) but then just go into some sort of infinite wait for connection mode, The MIFI device appears to be unaware of them, as it doesn't show any connection..
I did a full Network reset with the iPad, and it connected just fine - once. The next time I turned it on, the same problem occurred. I'm not going to do a full reset with my iPhone unless I have reason to believe this problem is solved.