ios 6.1.5 ipod touch 4th generation jailbreak problems

[iMore Question]

i have followed through every step of redsnow's jailbreak process (using the application on a mac). it has said that the jailbreak is successful, it then prompts me to reboot the device by going into DFU mode. after doing this it says "Done! the rest of the process will take place on your device" however after it has finished the process Cydia is not installed on my device and it does not seem any different to before. P.S. i made sure to check the box saying "Install Cydia when jailbreaking"

 

[iOS Gravity]

Use P0sixpwn.

 

[jamontoast456]

I have tried using the P0sixpwn jailbreaking tool but whenever I plug in my iPod it says "this device seems to already be jailbroken".
I have also tried to restore my iPod to factory settings through iTunes twice (so that it would be 'un-jailbroken'), however it still says that my device is "already jailbroken"

 

[iOS Gravity]

Not sure what to say... Try again with RedSn0w.