Another one of those "Whacko" answers . .
The Boonex chat uses Flash and the latest browser updates make it harder and harder to implement flash. My Chat also stopped working a week or so ago both on Chrome and Firefox. It took well over an hour to get Flash running on both browsers and get Chat back again. Both browsers now see to switch Flash off by default and request you to implement it when needed. Sometimes the request can go unnoticed.
Getting it to work again involved uploading the latest version of Flash and playing with settings in Chrome and Firefox. keep in mind that this will be something every member on your site will also have to do.
In the end I removed Chat because as one person said, all the people in chat rooms do is talk utter crap.
I'm relying on Simple Messenger and Simple Chat 2, the latter being a commercial module from AntonLV. Both are one-on-one chat and both work fine in their own different ways.