Gun continues firing after Wire input is set to 0

What steps will reproduce the problem?
1. Create an ACF gun and link up appropriate ammo (Self-wire the Active input 
on the ammo crate).

2. Make an Expression 2 as follows:

@inputs FireIN Ready Unlock
@outputs FireOUT
@persist Allow
if(first())
{
    Allow = 1
}
if(!Ready & ~Ready)
{
Allow = 0
}
if(Unlock & ~Unlock)
{
Allow = 1
}
FireOUT = FireIN * Allow

3. Connect FireIN and Unlock to numpad inputs. Connect Ready to the gun's Ready 
output. Connect the gun's Fire input to FireOUT.

4. Trigger the FireIN input.

What is the expected output? What do you see instead?

The gun should only fire once and require the Unlock input to be triggered 
before being fired again.

What happens instead is the gun continues firing as if its Fire input was 
constantly receiving a signal of 1. It continues to do so even after the 
expression gate is reset or removed entirely (might be a Wire issue, might not.)

Original issue reported on code.google.com by lazerman...@gmail.com on 2 May 2012 at 7:00

Pmarzec2000 / acf

Gun continues firing after Wire input is set to 0 #10