Why is this happing? -Script only works some of the time-

I have a particle generator script with a flight check to turn them on and off.
I have 4 exits for the particle flame to spawn. After playing with one of the 4 exits(mainly changing the color) i got it to turn off the particles when not flying.
So I saved the script and gave it to my 3 other exits. Now when I first put the jet-pack on the particles are not on (like its suppose to be) then when I fly they come on. When I land only the 1 exit turns off and the others keep spawning. When i first had the script all 4 of them was like that, would turn on but not off. I added a llOwnerSays to both the on and off "If"-lines to see if it just was not reaching the off line. I pinpointed the problem through a few exparaments, the "llParticleSystem( [] );" was not removing the particles.

integer isFlying = FALSE;

StartFlames()                
{                
    llParticleSystem([                    
        PSYS_PART_FLAGS , 0 
    | PSYS_PART_INTERP_COLOR_MASK      
    | PSYS_PART_INTERP_SCALE_MASK       
    | PSYS_PART_FOLLOW_SRC_MASK         
    | PSYS_PART_FOLLOW_VELOCITY_MASK    
    | PSYS_PART_EMISSIVE_MASK            
    ,
    
    PSYS_SRC_PATTERN,           PSYS_SRC_PATTERN_ANGLE_CONE
    
    ,PSYS_SRC_TEXTURE,           "lavafl1"                 
    ,PSYS_SRC_MAX_AGE,           0.0                
    ,PSYS_PART_MAX_AGE,          1.0                
    ,PSYS_SRC_BURST_RATE,        0.02               
    ,PSYS_SRC_BURST_PART_COUNT,  2                  
    ,PSYS_SRC_BURST_RADIUS,      5.0                
    ,PSYS_SRC_BURST_SPEED_MIN,   -1.5               
    ,PSYS_SRC_BURST_SPEED_MAX,   4.0                
    ,PSYS_SRC_ACCEL,             <0.0,0.0,-0.8>     
    ,PSYS_PART_START_COLOR,      <0.40,0.0,0.40>     
    ,PSYS_PART_END_COLOR,        <1.0,1.0,1.0>      
    ,PSYS_PART_START_ALPHA,      0.9                
    ,PSYS_PART_END_ALPHA,        0.0                
    ,PSYS_PART_START_SCALE,      <0.4,0.4,0.0>      
    ,PSYS_PART_END_SCALE,        <0.3,0.3,0.0>      
    ,PSYS_SRC_ANGLE_BEGIN,       PI                 
    ,PSYS_SRC_ANGLE_END,         PI                 
    ,PSYS_SRC_OMEGA,             <0.0,0.0,0.0>       
            ]);
}

default
{    
    state_entry()
     {
           llSetTimerEvent( 1 ) ;
     }

     timer()
     {
           if( (llGetAgentInfo( llGetOwner() ) & AGENT_FLYING) && !isFlying )
          {
               StartFlames() ;
               isFlying = TRUE;
               llOwnerSay("Turning On");              
          }

          else if( !(llGetAgentInfo( llGetOwner() ) & AGENT_FLYING) && isFlying )
          {
               llParticleSystem([]);
               isFlying = FALSE;
               llOwnerSay("Turning Off");
          }
     }
}

The script was originaly a freebie script so there was lots and lots of notes to help newbs like my self out when we read it. I went ahead and deleted all the notes so it would be easer for you all to read.
Like I said this is the exact same script all 4 exits have but only 1 works properly

There has been a bug reported in the particle system with the latest release of the client.


Try recompiling the scripts, it may help.