Interrupt perseverates

I am attempting to create a simple interrupt-driven RF24-based remote that sends a 2 byte code when one of two buttons is pressed. The receiver is a raspberry pi running RF24 code that has been written for the pi. I have adapted the code for the arduino remote from different forum posts and it partly works. The problem is that if I repeatedly press one interrupt’s button (4-5 times), then press the other interrupt’s button, the receiver still receives the transmission from the first interrupt for 1-2 times. Any idea what I am doing wrong? Code below:

/*
 atmega328p
 internal osc 8mhz w/ cpudiv8 3-4volts
 fuses:
 extended 0xFF
 High 0xD9
 Low 0x62
*/

 #include <avr/interrupt.h>
 #include <avr/sleep.h>
 #include <Arduino.h>
 #include <SPI.h>
 #include <avr/power.h>
 #include "RF24.h"

 int led = 5;
 volatile byte int_flag;
 int wakePin0 = 2; 
 int wakePin1 = 3; 
 byte count = 0;  // counter

// ce,csn pins
RF24 radio(9,10);

void setflag0()        // int0
{
	int_flag=0;
}
void setflag1()        // int1
{
	int_flag=1;
}

void setup()
{
    int_flag = 9;
    pinMode(wakePin0, INPUT);//
    pinMode(wakePin1, INPUT);//
    pinMode(led, OUTPUT);

    attachInterrupt(0, setflag0, LOW); 
    attachInterrupt(1, setflag1, LOW);
  	// init radio for writing
  	radio.begin();
  	radio.enableDynamicPayloads();
  	radio.setAutoAck(1);
  	radio.setRetries(15,15);
  	radio.setDataRate(RF24_250KBPS);
  	radio.setPALevel(RF24_PA_MAX);
  	radio.setChannel(76);
  	radio.openWritingPipe(0xF0F0F0F0E1LL);
}

void sleepNow()
{
    set_sleep_mode(SLEEP_MODE_PWR_DOWN);
    sleep_enable();         
    attachInterrupt(0,setflag0, LOW); 
    attachInterrupt(1,setflag1, LOW);
    sleep_mode();         
	sleep_cpu();  
		                             // Wakes up here??
    sleep_disable();                               
    detachInterrupt(0);     
    detachInterrupt(1);    
}

void loop()
{
switch (int_flag)  {
	case 1:
		int_flag = 9;
		radio.powerUp();
		digitalWrite(5,HIGH);
		radio.write("OFF",3);
		digitalWrite(5,LOW);
		radio.powerDown();
	    break;
	case 0:
		int_flag = 9;
		radio.powerUp();
		digitalWrite(5,HIGH);
		radio.write("ON",3);
		digitalWrite(5,LOW);
		radio.powerDown();
	    break;
}
     count++;
      delay(100); //the shorter the delay the worse the  problem with prev flag continuing to be sent when trigger other interrupt
      count = 0;
      sleepNow();   
    if (count >= 2) {
      count = 0;
      sleepNow();     // sleep function called here
  }
}

remove radio.powerUp and .powerDown. The rf24 library itselfs keeps radio powered down when not transmitting and not in listening mode.

    attachInterrupt(0, setflag0, LOW); 
    attachInterrupt(1, setflag1, LOW);

Using LOW is a poor idea. Use CHANGE, FALLING, or RISING, instead, depending on which edge you want as the trigger. You'll have noticed that there is no HIGH value that can be used. You might investigate why, for a clue as to why using LOW is a bad idea.

Thank you for your replies.!
Removing radio.powerDown unfortunately had no beneficial effect.
Changing the trigger and sleep mode :

    attachInterrupt(0,setflag0, FALLING); 
    attachInterrupt(1,setflag1, FALLING);

and

//    set_sleep_mode(SLEEP_MODE_PWR_DOWN); problem
//	set_sleep_mode(SLEEP_MODE_STANDBY);//problem
	set_sleep_mode(SLEEP_MODE_PWR_SAVE);//works slightly better, less perseveration but definitely still occurs and twice as power hungry.

only helped slightly, leading me to conclude there is some other bug. Any further ideas?

It seems to be working fine now. The fix was preventing the receiver from delaying 1 second (removed sleep(1) in the raspberry pi code though now it's uses 100% of the pi's cpu time and I'll have to figure out what to do about that).
Also, as suggested by PaulS, I'm using FALLING instead of LOW for the trigger condition on the transmitter's interrupt. I thought I had read that SLEEP_MODE_PWR_DOWN required a LOW interrupt but that turns out not to be the case. Thanks a million for nudging me in the right direction!