I have the same problem to.there is no install and delete in the fbi.the only option is Delete/Rename/Copy/Paste.the games I've try to install.they install on another 3ds.im confused..
Had a 3ds on 1.0 and done the update firmware to 5.1 with frozen cart.ive follow the 3ds guide to decrypt the browser put the files in the files9 folder but it won't open the browser.its say update via Internet.cheers