I have encountered a strange case in which opening a jpg file that is stored on a mapped drive causes Photo Viewer to display the contents of a different file. This occurs on a 32-bit Win7 system accessing a folder share hosted on a system running XP sp3. The problemoccurred after I: Installed the vista drivers and tools for a Canon LiDE 500F image scanner on the windows 7 system. Used explorer on the win 7 machine to map a network drive on the xp machine using a UNC path (specifically, "\\10.1.1.123\Early L&L Photos"). Launched the scanner app and gave it the drive letter of the network drive to use as the destination directory for scanned images. Began scanning images. After each image is scanned, this app attempts to launch an explorer instance targeted at the newly created file. Scanned another image while leaving open the explorer instance previously launched by the app. Double-clicked on the newly added filename. Observed Photo Viewer launch and display the contents of a different image. If I close the explorer window after an image is scanned, the problem does not occur. That is, when the next image is scanned, the app launches a new explorer instance and double-clicking on the new file name launches Photo Viewer and displays the correct image. Also possibly worth noting is that when the explorer window is left open while a new image is scanned, it appears that the app creates a temp file in the target directory which is then renamed as (or is replaced by) the final file. So explorer must be getting a number of notifications about the file in question.