keyboard stops responding intermittently when using VNC to access macbook pro?

[Greg Hauptmann]

I use VNC to remotely access the screen/keyboard of my MacBook Pro,
running the latest version of OSX. Intermittently (which is annoying)
the keyboard stops working, and at this time the mouse is still
working fine.

Any ideas why/when/how my MacBook may stop responding to keyboard
presses from (a) remote PC using VNC to access and (b) the virtual
keyboard?

Any fault finding ideas? Any known issues?

thanks