Hmm, that should be the same 555 I used in core which seems to be the correct part spacing (some of the user generated parts have either offset from the grid or have incorrect spacing issues but most that you find in the parts bin are pretty good). Is your grid perhaps in mm rather than in in the view set grid size window (although that doesn't work out either ...)? If you would save the sketch then upload the resulting fzz file (7th button from the left on the tool bar at the top of the reply window) we can have a look at the parts and see if we can see a problem.
Perhaps one of our Mac users can provide illumination, but I think this is the first case like this that I have heard of. However if .07 is working thats good 
Peter