Logitech wireless mouse and keybord hang on startup

HI, I have logitech Wireless 3100Mx keyboard and mouse installed on windows
vista ultimate 32 bits, using setpoint drivers 4

My issue is on startup or wake from sleep state, I get no response from
mouse or keyboard being unable to move the cursor or hit a command key,
though devices are working and remote base recognize them as "connected",
Vista just ignore them and all I can do is reboot PC from case power button...

This happen very often but not everytime and I have to start in "safe mode"
then restart computer to get devices work again, sometimes I only get mouse
and no keyboard, then I have to end session (not reboot) and re-open to get
both working.

I tried as many windows update as I could, scanned for Virus and the likes
(Mc Afee internet suite) and kept my drivers up to date, including Logitech's
one, to no avail...

This issue looks really peculiar to me and its random occurence puzzle me...

Is there any way to get rid of this ?

Thank you.