Hello sgunhouse,
Thanks for your reply.
What do you mean by "permissions"?
In the phone's filemanager there is no ".opera"-directory, neither is one when I browse the content of the phone's memory by my pc's file manager.
Maybe this is due to the fact that the browser is not a third-party application but was preinstalled and is thus assumingly part of the firmware.
Do you have an idea, how I can solve my problem?