Sorry, the "Xperia X10" is compatible with Firefox, but the "Xperia X10 Mini" is not compatible. I've added this phone to the list at https://wiki.mozilla.org/Mobile/Platforms/Android#System_Requirements

Hello my name is andreas and I live in sweden and I am disappointed about this because you just said it don't work are you working to fix it or what we don't get any information about the problem and when I downloaded the install so was there that said it worked on sony ericsson x10 and mini and mini pro so I really hopes that you try to fix it because I love to use firefox I don't use any else webb browser // killerax