I confirm than I am using now the latest upstream kernel as advised and I continue to have the same problem. I hadn't used Ubuntu before so I can't confirm that the problem didn't exist in some previous kernel. I am adding the 'kernel-bug-exists-upstream' tag as said.
I confirm than I am using now the latest upstream kernel as advised and I continue to have the same problem. I hadn't used Ubuntu before so I can't confirm that the problem didn't exist in some previous kernel. I am adding the 'kernel- bug-exists- upstream' tag as said.