prompted to download octet-stream

Hi -

I have a rails site which works fine on my dev machine, works fine on
my host with ie6, but with firefox, on certain pages, it prompts me to
download an octet-stream. Anyone ever seen this and any ideas why?

If not, can anyone suggest what steps I should take to figure out
why? In other words, where should I look, what and how should I be
logging, if anything, to diagnose the problem?

Thanks,
Dino

In case anyone has this problem, switching from fcgi to to Passenger
solved this.