Are you sure you haven't modded some files?
Since 0.91 at least (probably since 0.9) the triggers are as follows:

Code:
;------------------------------------------
Trigger knight_crusader_vnv_trigger
    WhenToTest CharacterTurnEnd
    Condition AgentType = priest
          and I_CrusadeInProgress
          and IsRegionCrusadeTarget
          and CharacterReligion catholic
          and TimeInRegion > 1

    AcquireAncillary knight_crusader chance  33 

;------------------------------------------
Code:
;------------------------------------------
Trigger priestinit4
    WhenToTest AgentCreated

    Condition AgentType = priest
          and SettlementBuildingExists >= cathedral
          and Trait PriestLevel = 0

    Affects PriestLevel  1  Chance  100 
    Affects NaturalPriestSkill  1  Chance  10 

;------------------------------------------
Trigger priestinit4_orthodox
    WhenToTest AgentCreated

    Condition AgentType = priest
          and SettlementBuildingExists >= cathedral_o
          and Trait PriestLevel = 0

    Affects PriestLevel  1  Chance  100 
    Affects NaturalPriestSkill  1  Chance  10 

;------------------------------------------
Trigger priestinit4b
    WhenToTest AgentCreated

    Condition AgentType = priest
          and SettlementBuildingExists >= jama

    Affects NaturalPriestSkill  1  Chance  50 
    Affects Dogmatic  1  Chance  50 

;------------------------------------------
So as you see, muslims cannot get Bishop nor crusader knights.