I have had the following issues:
Seas0npass not installing
ATV for 4.3 not installing after jailbreak: Installer can not find device
After 2 days I have just got it to work.
1) Use Sn0wbreeze not Seas0npass to Jailbreak: This started out fairly easy but I had issues identifying the IPSW file. But got there in the end. Updated nitoTV. Installed openssh.
2) atvflash install did not connect to the device, although the correct ip address was being shown. So, and bear with me here, I thought I would try and install via ssh. Installed Cyberduck. Followed instructions on this site to gain connection. Tried conecting with device ip address - connection denied. Used appleTV.local and connected.
Whilst Cyberduck still had connection - Thought, Hang on, just maybe, just.... that gaining connection might now allow atvflash installer to work. AND IT DID!!!!!!!!
JAILBROKEN & ATVFLASH INSTALLED - THANK THE LORD !!!
THERE ARE SOME SERIOUS ISSUES WITH SEAS0NPASS AND ATVFLASH FOR 4.3. AND NOT A LOT OF COMMENT THAT THE ISSUES ARE BEING DEALT WITH. HACKING IS ALWAYS PLAYING CATCH UP, I UNDERSTAND, BUT A LOT OF PAYING CUSTOMERS ARE VERY FRUSTRATED.