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This is a small issue, but it comes up occasionally… doesn’t happen if you’re working with Office 2003, but a lot of people are not.

If you are working with Word XP, the following may happen. You click on a document name in a document library and view the contents. You decide that you’re going to edit the document. So, you close it down, and then use the “edit in Word” feature of the document libraries. You make your changes and save, and close.

Then, you reconsider your changes, perhaps you just want to re-check the document, so you open it up just by clicking the link to open it in read only view.

Most likely, you’ll see the version of the document from before your edits. I’ve had a few distraught phone calls from users who experience this. The edits have been saved however, whats happened is IE has opened the locally cached version of the document from your first viewing.

If you shut down all your browser windows, open a fresh browser, open the document, you’ll most likely see the correct latest version.

So, whats the fix? Well, as documents are delivered by owssvr.dll, there’s only so much you can do. In IIS, specially on the owssvr.dll file, I disabled the default caching rules and added ‘cache-control:no-cache’ to the http header. Problem fixed.

But, (and it’s a big one) do you really want to disable caching on all your lists, web part pages, and documents? Probably not. Owssvr.dll is responsable for all these pages. (check out your iis logs) I’ve not done detailed performance checking on this, but it can only increase the workload of the server. How significantly is difficult to say.

Perhaps there is a more subtle cache-control command I could add to the http header as ‘no-cache’ is a bit of a sledgehammer, but it’s worth checking how common an issue this is before making such a change.

Either way, I’m glad I found out why it was happening…