Let me say this about that...The unfortunate reality is theres a chance because theres a timeframe here, but theres also a chance hes just butthurt because he hasn't got help, and on that case shame on him for lying about something so serious. I get being frustrated I do. But its still negligence
But the simple fact of the matter is even if he is being truthful, nobody forces you to mod. A ZX300. Its good enough of a DAP for Sony to sell as such is still considered high end by corporate standards. This is not fault of Sony, this is fault by user negligence, any action you take to modify or alter a device you are knowingly taking said risk and you are responsible for anything that goes wrong. MrWalkman is not accountable for another users negligence, I even vaguely remember that message being included somewhere on firmware.
Moving on. MrWalkman didn't owe it to anybody. If you read over the instructions everything is pretty well documented and if you do everything by the book you are almost guaranteed to not have complications. Many of us have changed countless times, and even been booplooped several testing betas and he had helped me, but he simply could have walked away. MrWalkman has always done it out of his own kindness.
He could have never gave us firmware that has changed the whole playing field, or he could have charged people for it and we never would've known any better. It shpuld be well understood though the user is at fault for their actions any not anybody else.
From MrWalkman on down to the least knowledgeable users in this forum; they are all here to help. But, there is an immutable and time-honored tenet in these forums (all, really)--we are all here to help each other, but it works best when those requiring help understand that they have to help themselves along the way. Tossing out an "I have a problem..." and expecting everyone to jump to your aid isn't going to go far. When I did telephone technical support back in the day, my first question to callers was, "What page of the manual are you on?" I was telling the user(s) that I expected that they'd done some research and tried to help themselves. (If you guessed that very few had cracked a manual, you'd be correct...)
And on the topic of Sony's ZX300--I just looked at eBay and there are many units for sale there for around $250.00 - $350.00 USD. If I'd been waiting this long for aid and got none, I'd consider purchasing a used device and cutting my losses. I'd think long and hard about modding it--perhaps I'm not understanding the process well enough, so just use it stock.
These are just my opinions... I could be wrong.