I don't know if anyone else has mentioned this but I cannot see my own whispers in the chat screen but people do reply so they are getting sent.
I have read about this a bit on some forums has anyone figured out which mod is causing this problem I don't think its NUI because a few of my guildies are having the problem and they don't use NUI.
Someone in my guild was getting the same problem. Which chat addon are you using if any ? I use prat and had no problems receiving or sending whispers.
I'm definitely missing WIM though as thats bugging out at the moment.