I'm not sure if this has been discussed I found some reference to it a month ago or so elsewhere,
I'm running 2010-11 on a windows 7 64 bit setup. FFEPlus regularly fails to run, sparse solver always functions correctly, but FFEPlus doesn't even start an analysis, it instantly brings up the old 'study failed' message.
I remember reading somewhere about long file path names to the results folder, and have tried shortening this but with limited succes. Sometimes FFE runs perfectly but more often than not nothing happens and it is frustrating when running accurate meshes which sparse solver takes an age over.