I tried it with your tutorial but it`s the same again it only shows "Tx failed" like the other code...
Source File /mnt/sdb1/SGT-Prog/Arduino/ForumDemos/nRF24Tutorial/SimpleTxAckPayload.ino
SimpleTxAckPayload Starting
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
Data Sent Message 0 Tx failed
I also tried it with a 10uF Capacitor between Ground and Power but still no success 