Firefox appends .xls to a csv download

[breaknrun12]

When I try to open a .csv file from Firefox using Excel, firefox appends a .xls (filename.csv.xls) to the file and puts all the test in one column. How can I get Firefox to stop doing this so that Excel treats it as a true csv file.

Thanks,

 

[smah]

Does this happen when dowloading from different servers? It's possible that the server's mime type setting is causing this behavior. Does it happen on different client machines with & without Excel or with different browsers?

 

[breaknrun12]

It only happens on a handful of clients. the application we are using only uses firefox, so I can't use other browsers.