I installed Wubi on my HP laptop with Windows 7 for dual boot. It is fine for the booting, running Ubuntu, etc. Until that, after I shutdown from Ubuntu, the USB power still running on my cooler. I tried all the 3 USB ports and also different cooler, all the USB port still power on. And I confirmed that my laptop is shutdown completely, without any light on it.
I think it is Ubuntu shutdown problem. So, I tried to boot into Windows 7 and shutdown, but the problem remains.
So, my final solution was took off the battery, then plug the battery back, and only that, the USB is not running.
Please help me diagnose the problem and the solution of shutting down with Ubuntu. I quite afraid that shutdown with Ubuntu will cause any other problem.