Thanks again for your response and attention.
Actually when I first installed Booster it was not compressing XLS files at all. I read the manual and did exactly what you described in your post.
I am examining the Domino response in Firefox and Internet Explorer using Firebug and Fiddler. The original file, was 1MB in size. When I changed the parameters above to compress application/vnd.ms-excel, I can see that Web Booster is serving the file with a slight compression, dropping the file size to around 900kb. The response headers prove that the file has been gzipped.
When I use the servlet code that I sent you, I get the same gzipped response but with 300kb !
If you are also using GZipOutputStream in your code, I'm not quite sure where the problem is... Jdk version, maybe ??
My Web Booster version is 2.98, which I think is failry recent...
Any ideas ?
Sorry for all the trouble.