File Downloads Stop

Question

I have a 2010 Mac Mini, running Lion (although the problem existed on Snow Leopard).  Network functionality seems to be fine except for download files, either in a browser (tried several) or using Software Update.  The download starts, gets a meg or two into it and just stops.  Sometimes it will pick up a little, then stop again.  Not always in the same place.  Happens with both wired and wireless connections.  Other Macs on the network have no issues.
It's NOT losing connectivity, I can continue browsing while the download is stuck.
Can't find anything online, any suggestions?

Answer 1

Hey @silvergc, I've tried caffeine for a while and it seems to work, but what I've been trying to set up is some default pass for my torrent client — much as iTunes automatically prevents my MB from going to sleep while playing music.
For this purpose, I've used both $ pmset and $ caffeinate commands in Terminal (see: http://useyourloaf.com/blog/2012/08/09/keeping-mountain-lion-awake.html ) but unfortunately the end result is pretty much the same: if I quit Terminal the power assertion is cancelled and computer sleeps after preset interval of time.
(= whether using Caffeine, caffeinate commands or setting system preferences to "never" sleep, I end up having to manually configure/set this up every time, and turn off on task completion.)
I just wish there was a simpler way... Ideally, my Mac would sense when download is completed and then go to sleep (i.e. regardless if is still uploading). Any suggestions anyone?
@Jon I find it a bit weird that your computer stops downloading even on screen sleep (CPU still awake) since I haven't experienced this myself — can you tell me a bit more about the problem?