I upgraded gnome-keyring to 3.10.1-1ubuntu4.1 from trusty-proposed in a virtual machine.
Before upgrading and rebooting, this bug was occurring.
After rebooting, the bug was gone. I rebooted about 5 times and tested ssh keys using gnome-terminal (started both from the Dash and from Ctrl+Alt+T) and it worked every time.
I upgraded gnome-keyring to 3.10.1-1ubuntu4.1 from trusty-proposed in a virtual machine.
Before upgrading and rebooting, this bug was occurring.
After rebooting, the bug was gone. I rebooted about 5 times and tested ssh keys using gnome-terminal (started both from the Dash and from Ctrl+Alt+T) and it worked every time.
So, for me it's fixed!