I've had this problem with Mediafire which started occurring not too long ago which I don't recall ever having had when downloading from Mediafire and is connected to the internet wirelessly. There are times when downloading from Mediafire gets cut off when the download itself is about to get finished due to some reason. Looking at it, even when downloading at an optimum rate (in relation to the bandwidth subscription) and is already at around 90% or so of the download process, it just stops (0 kbps) but can be resumed. The resume function however is not all too reliable as it sometimes fail to actually resume the download process, in the end forcing you to re-start the whole download process. Note I usually encounter this only when I'm connected to the internet wirelessly and am using this laptop. I don't recall having the same issue on a separate computer that is connected wired to the internet.
Also, I don't recall having the same issue on some other file hosting sites such as jumbofiles, kiwi6, etc. .