I have fw 1.0 U in my 3ds
http://www.eurasia.nu/wiki/index.php/3DS_Games_with_firmware_updates_in_the_4.1_-_4.5_range
I cannot find a game eur with 4.x in my country...
You said your system was 1.0U
The U means United States of America.
If it's 1.0E, then it'd be Europe.