There is some kind of regression in the 2.7.2 version. When you send a message in the group chat, the message is actually sent, but the text is still in the input area and the message is not shown in the chat area. Also when a new message arrives into a room, it doesn't show it and only the tab title goes read. Same happens with the personal messages in the Group chat. Regular one on one chat works fine.
In 2.6.3 version there was a similar bug with regular messages, but it was only happening occasionally. After moving to 2.7.0 and Java 7 it was eliminated.