Problem: NEC ( now Renesas ) USB 3.0 controller dropping\un-loading it self from device manager.
My ASUS U3S6 card had this problem, since the firmware update the hub controller has not dropped\un-loaded at all. As of 8/2/2010, ASUS did not have the update on their support site.
Solution: Firmware update to Version 3.0.2.5.x.x
From
Readme.txt file:
CHANGES IN THIS RELEASE
Version 3.0.2.5
[New functions or enhancements]
- Mass Storage Class UAS (USB Attached SCSI) is supported.
[Problem fixes]
-Added the workaround of xHCI Driver Unload Problem.
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DETERMINING WHICH VERSION IS INSTALLED
[Windows Vista and Windows 7 and Windows XP]
1. On the Start menu, click All Programs, NEC Electronics,
USB3.0 Host Controller Driver, and then USB3.0 Hsot Controller Utility.
2. Show USB3.0 Host Controller Information. If "Firmware Version" is 3025,
you succeed in updating FW.
You can find the updates at various sites on the web, but here are a couple:
Lenovo support
Station-drivers < The one I used (Windows version)
Disclaimer: You flash your hardware at your own risk.
EDIT:
There is a new driver version for the NEC/Renesas USB 3.0 and it can be downloaded here @ Intel's download center: USB 3.0: Renesas Electronics* USB 3.0 Driver (Version 2..1.28.0)
or
you can get the
latest driver( version 2.1.36.0 ) here, @ Stationdrivers
The latest firmware is still version 3.0.2.8.0.8, as of, July 4, 2011. Can be had at Station-drivers here:
NEC/RENESAS USB3
All this info has been for the NEC/RENESAS USB3 uPD720200 & uPD720200a Controllers... Station Drivers ,also, has updates for the uPD720201 & uPD720202 chipsets on the same linked page.