@robko: thank you, I missed that setting

I'll search for linux support
@davidfor: I disabled wifi on my router since I don't need it...

I suscribed to the thread about kobo firmwares, if there will be an update I'll do it manually.
I know that on the site there's a lot of free books, but not in my language. Furthermore for what I know some free books should be preinstalled. Anyway I don't care, I have more trouble with first group of
problems I reported.
@meeera: it doesn't offer you search filters, like language and free books.
I want also to add that you must wait 1 - 1.5 seconds before some operations will be performed, like accessing to dictionary and turn off-on the device. It should be nice if those delays could be personalized, since they are too long for me.
Furthermore an app that let you write a text file it will be useful nd simple to add IMHO ^^