No remote context menu

I've got WinSCP v5.1.7 (Build 3446) installed on two desktop PCs both with same OS (Win8) motherboard and video card. I can get the remote context menu on one machine but not on the other, which just shows the local context menu. I've tried both the Commander and Explorer window interfaces with the same result. Any ideas?

Can you send me an email, so I can send you back a debug version of WinSCP to track the problem? Please include link back to this topic in your email. Also note in this topic that you have sent the email. Thanks.