I'm going to take a wild stab in the dark here and say that I think when we saw the AI traders break the universal bank it's because they were seeing High Demand as an insistence to take something to somewhere, and the station Commoditiy Markets don't actually behave in the way a real market does, by adjusting their demand level based on the actual fulfilment.
With this type of mechanism in place the AI traders, working 24/7 and not being bothered by such stuff as work or beer or toilet stops, continued to stock up the stations that had a high demand to the point we witnessed in Gamma, where it was quite possible to purchase gold from a High Tech station that was supposed to be importing it, as the good old AI had delivered more than enough for it to spill into the Sales side.
Meanwhile, it still showed as High Demand, and those pesky AI just kept at it, like a London Banker fiddling the Libor ratings, oblivious to the damage they were doing.
The only thing that was being impacted was the Value of the gold, or whatever else the AI was shifting, because the markets were becoming saturated in surplus stuff, thus driving down the average prices.
To fix this problem, at least in the shorterm, it seems that nothing is High Demand anymore.
My suspicion, based on my, what could well be flawed, reasoning, is that whilst the AI is being giving a lesson in the finer workings of economics, beer and the usefulness of bathroom breaks to prevent it doing this again, is that all the High Demand stuff has been changed to Medium Demand, and the AI Trader is taking a break while the devilish minds of FD reprogram its "I" to make it a little more friendly.
The actual stuff that had been already stuck on the various markets is however still there, slowly being eaten by whatever fiendish station thing is there to maintain a need for a perticular commodity, but still being in a large enough quantity across the universe to maintain the lower average prices and also make it slightly harder to make a profit in some places. Note, only in some, because in some places there will be enough real Commanders buying stuff to clear the individual markets back to how they should be.
I'm basing this loose and perculiar theory on the fact that I keep stumbling on stations that have a Medium or Low Demand for Commodities that can be bought from them, and I'm a good few light years away from the main trade areas.
It does seem to be getting better, it just doesn't look like it's happening very quickly. Maybe it time for some AI Pirates that Only target AI Traders? Lots of them!