Hi,
I am using PHPR 5.2 in Windows 7, but I think the same thing happens with PHPR 5.1 and other O/S (XP / Vista).
When pressing the ESC Key at any point the program closes. You may see this happen when in Visual Editor, or Initial Page.
Of course one may lose coding by this.
Regards,
QUALISYS SOFTWARE
Athanasios Alekizoglou