Clock Time Drift

[grotondo]

Hi to everyone!. Greetings from Argentina. This is my first post.
I have a 1 Gb. Nano Clone with usb connector on one side and 1.5 OLED.
It works just fine, but when I set the clock, and shut it down with Play button.
After 8 hours off, when I turn it on, the clock has drifted 1 hour ahead.
Player firmware is 3.5.37.

Any ideas??

Thanks.

[jp]

The clock function doesn't seem to work properly on any of these even if the power switch is left on and the player otherwise turned off.