device deconnection each time I touch .kobo folder

Hi everyone,

Has anyone experienced this since the last version of the firmware:

The Kobo device gets disconnected from computer in the 5 first seconds I try to copy a file inside the .kobo folder.

I thought it had something to do with windows, but it also happens on my raspberry pi (linux debian). Impossible to "upload" dictionnaries, or to copy the sqlite... I fear I won't be able to paste next firmware.

Any hint on what I can do to stop this ?

Regards

François