Posting here way after the topic was started for the benefit of others.
Asus software, like the drivers they write, is frequently buggy, and usually only updated for a few months after a computer's manufacture date, when it's frequently still buggy.
All the local Asus rep could tell me about Asus USB Charger Plus when quizzed during their short free-advice-after-purchase period was, "Oh, you're better off leaving all our supplied software running." I've learnt since from sad experience that this is about the opposite of the actual reality.
Asus USB Charger Plus is buggy. Here's a screencap of the program's options:
Looks like the it
might be handy,
if you could actually change options. But left, double-left and right clicks on the program icon in the system tray all get no response. The options window popped up only once in the 1.5 years I've had it running (and clicked in hope periodically). As also experienced by Mr Moonwalker above (no it wasn't
your fault mate). Oh, and there's no newer version at the Asus website, reinstalling it didn't help, the program doesn't get a mention in my laptop's manual, and it has no help file provided with it (at least Asus is consistent).
For those who for some strange reason want to keep running USB Charger Plus, the default settings are both options ticked, and Threshold Limit at 25%, if they happen to be what you want maybe it's of some use to you. Though since it charges devices faster, which is harder on batteries, it will wear them out faster.
Fortunately plugpacks for USB-powered devices are cheap, compact and lightweight, so there's no need to rely on this piece of unreliable Asus crapware while travelling.
Some nice 'gee whiz' spin from Asus
here on what seems to be the program under a previous name (trying to escape a bad rep?). And a user instruction, yay! Err... "To enable the charge function under S3, S4, S5 mode, make sure your... device is well connected to PC under S0 first." Yeah, I'll be sure to spend hours googling power modes and fiddling with BIOS settings so this crappy program can still not work properly.
Just uninstall it. I won't be buying Asus next time round, their sleep/hibernation works poorly on my laptop too, hanging, bluescreening or failing to boot about every second time, which I've learnt since purchase Asus are renowned for. They should test what they write properly.