Firefox issue

[Doug]

I am running Kubuntu 7.04 and have a strange issue with firefox 2.0.0.4.
 Anytime I download with it saving to disk it adds an extra extension to
the filename.  example file1.pdf gets saved as file1.pdf.pdf.  Doesn't
matter what the 3 letter extension is.  Doesn't matter if it 2 letters. 
file.gz gets save as file.gz.gz.  I can't find out out to fix this.

Thanks for any help you can give me.