My ISP is Virgin Media in the UK - who is yours marcopoly?
Please note that I (and others highlighting the problem) didn't experience problems with other filehosts.
I appreciate your input NOS911 but I suspect that the real reason is more likely to be that FF have expanded too rapidly for their server capacity, or have been having server reliability problems.
As regards number of complaints, I suspect that very few FF users are aware that this thread exists, and that the majority who have speed problems simply put up with it. I suspect that these comments are the tip of the iceberg - I wouldn't have mentioned it had I not been having other problems with FF, as had some of the other posters.