1608-I stuck on fetching http from tftpboot/16xxupgrade.txt

[g18c]

I am running CM 5.2 and adding a 1608-I to it (all other phones are 9608), the phone gets the IP then gets stuck on http//{cm-ip}:80/tftpboot/16xxupgrade.txt

I have seen Avaya 1600 IP Telephone Release 1.1 (March 2009

Inside it has the files:

16xxupgrade.txt
ha1608ua_1_100.bin
hb1608ua_1_100.bin
release.xml
.. and others ..

I believe the phones are certainly newer than this (and were running with IP Office before), any specific firmware i would want to use or am i good to go with the above, or is running newer firmware OK with older CM 5.2?

Also presume i can login via ssh dadmin and copy the files across - if its being fetched from http server would i place in /tftpboot/ folder, or is it some other location on the S8300D?

Thanks for help in advance.