This is a bug that used to occur on some graphics software with Vista. Vista has a device driver error detection scheme, and resets the driver to prevent system failure. This is not a problem for most software which neither causes the problem and recovers without error. Blender doesn't recover. Second Life both doesn't recover and causes the problem. In some way you are managing the graphics is causing the video driver to time out. Probably the result of holding a semaphore or other synchronization device while processing some telecommunications with the server. When it occurs it seems to occur repeatedly, other times not at all. Probably the result of either processing delays in your system or over the Internet and/or local ISPs. It shows as device driver reset and Second Life just hangs. This probably the result of Second Life holding a semaphore or other local synchronization device in the client while doing some communication with the server. Your software should be corrected to a) NOT CAUSE THE PROBLEM, and b) recover from the problem. This is probably the cause of many crash bugs where no crash log is created. It had seemed to get better for a while but recently has gotten much worse, either do to a programming change on the client or the server. In either event, the client should be modified so it never occurs and it recovers if it occurs for reasons not related to Second Life. NVIDIA statement on TDR Error Messages Some Windows Vista users have reported that their systems are displaying an error message that says: "Display driver stopped responding, but has successfully recovered." This is called a Timeout Detection and Recovery error message. Timeout Detection and Recovery (TDR) is a new feature of Windows Vista that attempts to detect problematic situations and recover to a functional desktop without forcing a reboot. Hangs can occur when the GPU is processing intensive graphics operations, typically during gameplay, and nothing is being updated on the monitor. To the user it appears that the system is frozen with no resolution to the problem; in previous operating systems users generally had to wait a few seconds and then reboot. The TDR error message "Display driver stopped responding and has recovered" lets the user know that the NVIDIA display driver (specifically the "nvlddmkm.sys" file) has been re-initialized and the GPU is reset without requiring a reboot. The only visible artifact from the recovery is a screen flicker, the result of a screen redraw. Note that some older Microsoft DirectX applications may render to a black screen at the end of the TDR, requiring the user to restart these applications. TDRs are not specific to a single driver problem, and can occur for a variety of reasons. When they occur, diagnostic information is collected in the form of a debug report that is sent to Microsoft through the Online Crash Analysis (OCA) mechanism if the user opts to provide feedback. NVIDIA encourages users to submit their own bug reports via the NVIDIA Vista Quality Assurance Program, using the keyword "TDR" in the description of the problem. The NVIDIA bug report link is here: https://surveys.nvidia.com/index.jsp?pi=749...8f09e040b4a437a We understand that many users have expressed frustration with this issue, and we apologize for the inconvenience. Since the NVIDIA v101.41 beta driver release, NVIDIA has been fixing many TDR issues reported by users. Our software team is currently preparing a new driver which will dramatically reduce the number of TDR errors that users have reported on the forums. Thank you for your patience. More information on TDRs can be found here: http://www.microsoft.com/whdc/device/displ...dm_timeout.mspx.