I bought my chips in ebay, so they might be fakes.
Maybe I should try disconecting the termination resistors, but this doesn't look like a neat solution.
I'm also using CAT5e cable that it's almost 200 feet long.
So long they work, and the thing is that only the ones acting as drivers get hot, the ones receiving are cool.
I'm sending shiftout signals with a 3 microsecond delay, so I asume something like 333KBps. But I also use one as a latch, so the tranfer rate is way slower, and all of them get equally hot.