dreamcast region free or not

[247]

So, two days ago i've discovered my pal dreamcast is region free, but in reality it's not. While it is, or maybe not...
Well i'm getting seriously confused so let me clear things a bit...

Two days ago i've mistakenly powered my pal dreamcast with the Shutoku Battle 2 disc inside (jap game of course) and to my great surprise it was working without the need of the xploder cd, Powered off and on again, and it was just working like a charm.
On the evening i powered off the console and to my surprise it was not working, as i needed the xploder disc again. i turned off the console pulled the plug off the wall, reinserted again, and ntscu/j games were working like a charm without the bootloader.
Yesterday lunch they were working while yesterday evening they were not, and today they are working just fine.

now the question is : how the hell do i know what happened to my dc?maybe the previous owner modded something?i do not have any switch anyway and the case is completely standard and untouched...maybe i need to open the console?

[HuntrRose]

maybe its haunted?