Ok, thank you for the information but I think it would be good to mention somewhere and be mentioned in the error message.

The scope does not lose the connection until to 5000s/div even with limited "low speed" USB connection.

That's OK,
Sorry, I had not made ​​the connection between the message and the setting (maybe it should be indicated in the error message)
Now I can even select up to 5000 s / div. EXTRA !!!

Thank you again Martyn

Thank Martyn, "Does this happen every time you switch to 100ms/div ?" - This happens when I spend 100ms/div to 200ms/div and beyond, until 100ms/div is good. "Have you tried unplugging and replugging the cable ? Does this re establish contact ?" - The contact is restored simply by reselecting the Pi...

Hello, Why I get the message "Check USB cable" when I select the time base to more than 100 ms/div ? and when I click on the only "Cancel" button, I have to reselect the oscilloscope. My settings: - Windows XP Pro SP3 - PicoScope 6 Version 6.8.6.9 - PicoScope 2204A model, CW350/364 Thank you for you...