Keyboard mapping ~only in Calibre~ is wrong

Hello;

I'm using Calibre as an ebook server on my headless media server (Ubuntu 14.04) I connect to the server machine using VNC. When typing text in Calibre (such as doing a search), many (but not all) of the keys appear to be incorrectly mapped.

This only occurs with Calibre as I have confirmed that in the same VNC session, the keyboard mapping is correct in other applications (such as Chrome and a general text editor.)

I cannot see any settings for keyboard mapping within Calibre which is why I'm posting here. Any suggestions?