Consider the following scenario.

• You have a computer that is running Windows Vista or Windows Server 2008.
• You plug a USB video device into a USB root hub that has the USB selective suspend setting enabled.
• An application uses the USB device while the device is in selective suspend mode.

In this scenario, you may have to wait five seconds before the USB device starts to work. During this period, the application that uses the USB device appears unresponsive. For example, when you run an application to use a USB camera that is in selective suspend mode, you may have to wait five seconds for the video to appear in the application.

This problem typically occurs on computers that have multiple processors, multiple cores, or the hyper-threading feature.

On a Windows Vista-based computer, you want to suspend a Distributed File System (DFS) share root or directory tree by using the SuspendRoot method. You expect that this operation requires you to have only the local administrator permission on the computer. However, you cannot suspend the DFS share root or directory tree unless you also have read permission to the DFS.

Consider the following scenario:

• On a ThinkPad X300 computer that is running Windows Vista, you enable the Disable optical drive option on the Power Management tab.
• You perform a suspend-and-resume cycle or a hibernate-and-wake cycle on the computer.

In this scenario, the computer’s optical disk drive is intermittently not displayed in My Computer or in Device Manager.

Consider the following scenario:

• You have an offline folder on a Windows Vista-based computer.
• You run an application that uses a client-side caching API to put this folder into suspend mode.

In this scenario, you expect that only this application can be used to make the offline folder work online. However, in Windows Explorer, the Work Online button remains visible and functional for the offline folder.

Consider the following scenario:

• A Bluetooth device is connected through a universal serial bus (USB) connection on a computer that is running Windows Vista.
• You perform a suspend-and-resume operation on the computer.

In this scenario, the Bluetooth device that is connected to the computer is unavailable. For example, if you open Device Manager and then look for the Bluetooth device, you cannot see the Bluetooth device. Windows Vista does not successfully detect the Bluetooth device.

When you use a portable Windows Vista-based computer, you may receive a Stop error message that resembles one of the following:

STOP: 0×000000E4 (0×00000002, parameter2, parameter3, parameter4)
STOP: 0×0000000A (parameter1, parameter2, parameter3, parameter4)

Notes:

• The parameters in the Stop error message vary, depending on the configuration of the computer and on the issue type.
• Not all “0×000000E4″ or “0×0000000A” Stop errors are caused by this problem.

This problem occurs if the following conditions are true:

• A USB camera device is integrated into the computer, or the device is connected to the computer through a USB cable.
• You resume the computer from long-term suspend mode. For example, the computer has been suspended for 30 minutes or more.
• The value of the computer’s ForceHCResetOnResume registry entry is 0.

On a Windows Vista-based computer that uses Universal Host Controller Interface (UHCI) USB controllers, a USB device takes a long time to resume from “selective suspend” mode. Usually, the USB device takes 500 to 1,200 milliseconds (ms) to resume from this mode.

Therefore, USB devices that are attached to the UHCI USB controller may take a long time to respond. For example, assume that you are using a fingerprint reader to capture user fingerprints. The fingerprint reader is attached to the UHCI USB controller on a Windows Vista-based computer. If the fingerprint reader is in “selective suspend” mode, the system may not capture the fingerprint after you swipe a finger on the receiver of the fingerprint reader. This behavior occurs because the fingerprint reader takes a long time to resume from “selective suspend” mode. You must swipe your finger again for the fingerprint reader to capture the fingerprint.

Note: Typically, it takes about 20 ms to resume from “selective suspend” mode when you use either of the following configurations:

• Microsoft Windows XP-based computers that use UHCI USB controllers
• Windows Vista-based computers that use Open Host Controller Interface (OCHI) USB controllers

Consider the following scenario. You have configured offline file folders on a computer that is running Windows Vista. At the same time that offline files are synchronized, the Windows Vista-based computer switches to suspend mode. Later, you try to synchronize offline files.

In this scenario, the operation to synchronize offline files appears to succeed. For example, the file metadata, such as file size, timestamp, and other metadata is identical. However, the files on the server are corrupted, and the file contents are randomly different.

On a Windows Vista-based computer that is running a USB composite device, you may receive a Stop error message that resembles the following:

STOP 0×000000FE (parameter1, parameter2, parameter3, parameter4)
BUGCODE_USB_DRIVER

This problem may occur if the USB composite device has the Selective Suspend feature enabled. This problem occurs even though the USB composite device supports the Selective Suspend feature.