We're getting this a lot lately.
- Windows 2008 Server
- Windows 7 & Vista Client PC's
- Microsoft Office 2007
When a user tries opening a file on our network drive (word doc, excel spreadsheet, etc) the software reports the file is locked by 'another user' even when it's not. They're also seeing random 'Sharing Violation' errors when trying to save files to the network.
Possibly the same manifestation of the problem shows up when a user tries saving a local, on their own drive, non-network files and they get 'Can not save due to a Sharing Violation'.
Best Answer
OK, after tracking down potential problems and testing solutions since this question was posted I have the answer...
Anything that accesses files in real time (antivirus, syncing, or indexing software) can potentially create problems with Microsoft Office files.
Microsoft Office creates temp (with and without a file extensions) files when saving. Overzealous realtime scanning programs sometimes see these temp files, try and read their contents, and in doing so initiate file locks. This causes instant problems when the parent application tries to convert the temp file back to its intended format.
From MSKB: Description of the way that Excel saves files
From MSKB: Description of how Word creates temporary files
Most av, indexing, and syncing software handle the temp files correctly; some don't. And some work fine on their own but not well together when watching the same folder. It's up to you to figure out what program is causing the issue in your environment. Hopefully this answer gives a guiding light in the right direction.
Update: Microsoft has released a couple hotfixes to address this issue.
Office 2007 Hotfix
Excel 2007 Hotfix
Instead of requesting the hotfixes from MS, search for them at The Hotfix Share.
FYI: Neither completely solves our problem but they do significantly reduce "sharing violation" frequency.