AppEngine does not serve some precompressed files.

[Marko Vuksanovic]

I have tried precompressing some files and uploading to AppEngine but some of them were not served gzipped even though client sent Accept-Encoding: gzip header. It's a file 5mb large by default and after it is compressed it s a bit more then 1Mb. The other files which are like 500k are server gzipped... Any reason for such behavior? Is this an AppEngine limit?