Serving Compressed Files Amazon vs Lightty

We are currently using amazon CloudFront to serve css and according to Amazon itself, Amazon CloudFront can serve both compressed and uncompressed files from an origin server. But while i check compression it shows everything fine in origin server but it shows notcompressed checking in the link with cloudfront.

e.g. http://www.port80software.com/tools/compresscheck.asp?url=http%3A%2F%2Fimgsrv.mydomain.com%2Fen-UK%2Fsomething.css

it would result with Compression status: (gzip)

while with cloudfront

http://www.port80software.com/tools/compresscheck.asp?url=http%3A%2F%2hereisit.cloudfront.net%2F%2Fsomething.css

Compression status: Uncompressed

Origin server is running lighttpd with mod_deflate however, allowed config is:

deflate.allowed_encodings      = ("bzip2", "gzip", "deflate")

[i would think, putting extra allowed encoding wont affect as such.]

Here i am clueless, what is the real issue.