Haha, i had to get here some time or another. The firmware in my new player (ST3500 chipset) had a load of bugs, so i decided to try a flash. I used the version that came with the Sigmatel update program, that was older than mine.
Flash went fine, but now the player is stuck with a white screen as long as i hold the power button down. Whoops.
The recovery mode trick - holding the play button down while connecting the player to the USB port - worked just fine, the player is recognized as a Player Recovery Device and i installed the necessary drivers. I can also see it as a removable disk, just that i can't access it.
The problem is that the Sigmatel updater gets stuck in the searching part and won't allow me to do anything. How can i get this solved?
Oh well, the easy fix would be to just return it to the store and say it was faulty to begin with, as it was discharged completely when i bought it and i had no way to test it at the store. But that ain't my way of doing things...
(although if they offer me a refund i might just do that as i found a better player for the same price :P)
Later edit: I can always re-switch the player to recovery mode, so i'll have a hack at my backed up firmware (filefixer doesn't work with mine) and see if i can get it running again.
Even later edit: I managed to restore flash drive capabilities, w00t!!! Hex editing the backup files works, i'm on the way of fully restoring my player.
And finally...
I have restored my player to full functionality
and actually increased its storage capacity from 1.85GB to 1.88GB by removing the garbage at the end of the original extracted files and flashing them. Now i realize how important can a good backup be!