Have Dual monitor setup with host ATI Radeon HD 4600 as primapr and USB 2.0 UGA as secondary.
Host is Windows 7 64-bit. USB 2.0 UGA driver is V5.6 from Windows update.
When returning from sleep both screens are black. Mouse cursor is visibleand can move across both displays. BUT noting I can do changes displays from black. until I remove the USB video adapter. Then the primary comes back to life.
After bringing the primary back to life Ican re-plug the USB 2.0 UGA and the secondary returns to operation.
In my setup I have no screen saver. So, the screen(s) go black when entering sleep.
To fix this problem I went to display Personalization and selected Screen Saver (even though I have none…). There I checked the box “On resume, display logon screen”.
With this option checked the Logon screen is shown when returning from sleep. After logon thesecond display (fed by the USB 2.0 UGA) also comes alive.
This should be a common problem that should be noted somewhere.