BitcoinTalk
No blocks downloaded - MS Security Essentials users please read

View all posts

External link

So that was responsible for keeping blocks from downloading?

The link: "Win32 CPU Cycles vs 'Live Protection' Engines"

For BitcoinFX, Live Protection was keeping it from getting CPU for generating coins.  You said your friend was getting 1400-1600 khash/s, so it was getting CPU.  I guess Live Protection must have been blocking some other part of the program then?