So like probably most of you I downloaded the 1.6.6 IDE and for some reason a program I am working on to read Ethernet settings from an SD card couldn't open the text file (initializes the SD card, but fails to open the file). I re-loaded 1.5.5r5 and it works fine. Tried re-installing 1.6.6 and still the same issue. Anyone else seeing this? I am using an Arduino.com Arduino Ethernet board (before you jump on me, Arduino.cc stopped making them and I needed one for this project).
Maybe it's a bug, maybe it just happens with that board, or maybe it's just me.