Hey folks we reported you before that Greenpois0n RC5 was released to do the untethered Jailbreak on the all the iDevices and then a beta 2 was released for MAC OS X and still people had faced some issues.
Now moments ago p0xininja Tweeted that:
Now the RC5 Beta3 is release for MAC OS X, so people who were facing Loader issues will not have any problems till now. You can download Greenpois0n RC5 beta from here and follow the guide here. And remember do the Redsn0w part if you want to Hacktivate only. Dont do that for Installing Cydia as the loader thing will be fixed.