Downloading at 12KB but downloaded MB stays the same?

[expatriate]

Best way to explain this is by an example.

Say I downloading a 250 MB file, and have around 100 MB downloaded. Hour after hour Limewire says I am downloading at 9 -12 KB but the file details climb up to maybe 100.50 downloaded and then falls down again to 98.xx. This happens continuously - up to 100.xx and back down to 98.xx only to climb up once again.

This happens on quite a few of my downloads.

What is going on?

Thanks.