Drools retraction is causing rule not to fire

Question

Hi,

I'm coming across some weird behavior in Drools 4.0.7, but maybe it's just cause I don't understand I how Drools works. Assume, there's a class "A" that has a property called "property".

As facts, I have the following list of A's: A1, property = 123 A2, property = 345 A3, property = 123

I have two rules as follows:

rule "Rule 1 - Remove all A's that have property set to 123"
  salience 1000
  lock-on-active true
when
  $listOfAs : ArrayList collect(A( property == "123" ))
then
  for (Object a: $listOfAs ) {  
      retract (a)
  }
end

rule "Rule 2 - Do stuff with remaining A's"
  salience 900
  lock-on-active true
when
  $listOfAs : ArrayList collect(A())
then
...
end

My understanding is "Rule 1" will remove the facts of class A that have property to 123. When it gets to "Rule 2", shouldn't the "listOfAs" only have that one A that remains (i.e. the one where property is set to "345"). What I'm noticing is that "Rule 2" just doesn't execute at all even though I'm assuming there is still one "A" object that hasn't been retracted. If I comment out the "retract" it executes "Rule 2" fine.

Am I missing something about these rules work?

Thanks. Justin