When downloading a word or powerpoint document from some (but not all) websites, the downloaded file is renamed to have a .dot or .pot extension added to the filename. http://www.sendspace.com/file/m0l2r1 is is an example of correct behaviour. To reproduce the aberrant behaviour email the document downloaded above to a gmail account, go to the gmail web interface and click the download link. The file is downloaded as webkit_test.doc.dot instead of webkit_test.doc. This behaviour also manifests itself in my Exchange web interface on-line email and a number of other private document sharing services I use. The behaviour is the same if the document is simply clicked on or is right clicked and "Save As" is chosen. Additional information: I am running the daily builds of webkit but this also happens in the latest version Safari. I have MS Office 2004 and 2008 installed on this machine. I have used the office web email interface extensively for the past 2 years and this was not the behaviour previously. However since I switched about between Firefox and Safari I couldn't say when this began.