bundled_resources plugin : slow download


I am using the bundled_resources plugin v0.9 from Duan Johnson.
It is a cool plugin that makes dynarch calendar, lightbox and some other
usefull javascript stuff easier to integrate in a Rails application.
However, I am experiencing load time problems while deploying on the
integration server.
Indeed, it seems that the plugin appends the session_id to js files. The
files are then very slow to download (2s for a 35K js file).
The problem doesn't happens with other js files.

Have you experienced this problem (or similar)?

Do you know how to fix it? (obvioulsy it is possible to modify the
bundled_resources lib, but I'd rather find another solution)

Thank you for your answer.