Edit grid: quirk in boolean fields

Hi developers! Hi Dave!

Testing RC1. Client is Win XP. Server is Debian Sarge.

I have come across a peculiar effect while editing boolean fields. With 
other fields, if you want to discard your changes while editing a field, 
you hit <esc> and the original value is back (as long as you haven't 
saved yet). Not so with boolean fields. Pressing <esc> leaves yields 
seemingly random results.
One of the most peculiar show cases:
I click with the mouse. Value is TRUE.
1st click only sets the focus.
2nd click --> NULL
3rd click --> FALSE
4th click --> TRUE (again)
If I hit <esc> now, I end up with FALSE (!). That wouldn't be by design, 
would it?

Regards
Erwin