I haven't seen a message like that, but then my machines have all had USB2 ports since I discovered USB.

The message may come from the memory stick itself, since it has to do a "handshake" with the computer to establish that it's there, and the stick maker may have incorporated the message.

It also may come from the PnP in the computer. Since for these simple devices each time you plug the stick in it's a "new device" I don't know of a way to configure it so the machine will know it's ok the next time you plug it in. When you unplug it, the configuration often will "go away" so it probably will repeat everything the next time you plug in.

With many USB devices, if you use the "Safely Remove Hardware" icon¹ in the System Tray to disconnect before you unplug a "configuration" is left on the machine that might "remember" that you want USB1.1; but that's just a guess. (Some USB devices don't show in the "disconnect" menu, which usually means they're straight PnP, with a new default hookup each time you plug in).

¹ the icon usually has a fat green arrow at the top. If the USB device does appear there, you should always do the disconnect using the icon before unplugging.

John