i‘m using this one from fs.com with an 6450, no issues so far.
SFP+ Transceiver Modul - Brocade 10G-SFPP-T kompatibel 10GBASE-T SFP+ Kupfer RJ-45 30m
Are you really using an utp cable for the connection? Maybe you should give a good shielded cable a try.
has anyone an idea if it´s possible to replace the complete PSU (main and POE) from an ICX6450-24P with parts from an ICX6400-EPS1500? Is it just the same main psu with 3 parallel POE supplies or am i missing something?
are you running an FCX Image? Maybe the experts can give you an hint. I‘ve updated an ICX6450-24P to the the latest *u Image, couldn‘t mention any reasonable increase in temperature besides the normal deviation.