Can't get my new 2012 to run smoothly.  I've got a 3.2 Ghz Intel i5 processor with video - 2 TB Hard Drive -16 GB memory - 64 bit Windows 7.  I've lowered the settings to most of what's recommended in options (graphics) to the 'older' or 'less powerful' systems. Still get a lot of jerking.  Wanted to DL some engines, but not if this can't be settled.  Any ideas of what I might be doing wrong?  With all the hype, I thought this would a great thing for my grandkid.  He still plays 04 & 06.    THANX GUYS