In the Call menu there are Dial, Answer, Hold, Resume and Hangup, but no Transfer. How do I go about transferring a call?
In the call tab, above the big buttons you should have an edit box with "Transfer" button on the right side. Enter the number of the extension you'd wish to transfer the call to and push the Transfer button.
I presume you mean the Dialpad, and there is an entry box at the bottom (its actually an editable combobox) but there is no transfer button - or at least there is no button marked transfer and if there is an icon it is not obvious that it means transfer.
For what it is worth I am using the Debian package (0.8.51.dfsg-2-1). I suppose something may be disabled in the config files, is there anything I should be looking for.