T40 - needs reboot after long Standby

[syrenab]

I just bought a T40, everything works perfectly, except one small problem:
After Standby overnight, everything works except needs reboot to connect to Internet, although WiFi working with good signal.
Short Standby, whether Fn-F4 or automatic works fine.
Never ran into this situation before - on A20, T20, T22, T30
Any ideas?