We're using IE and an ASP.NET web application to open Word documents stored on a shared directory on a server. From ASP.NET we're passing the path to the file (\\server\path\file.doc) and in Word 2007 and older, using any version of IE, this works, even for multiple files at once. In Word 2010, using IE 8 (Win 7), when opening a single file, it works, most of the time. When opening multiple files, which is more likely case with our application, Word will sometimes open all, sometimes none, other times it could open any combination of the files. We've tried adding the server directory, subdirectories to the trust center, we've run with no add-ons for Word and IE. This issue seems to be restricted to Word 2010, but if there is any possible way for a work around, we need to find it.
I have recreated the issue with a sample app that simply opens files in a folder. I'm willing to share this, if it will help, but I cannot share the production app code.