Hello 
I was previously using Blender on a PC and I recently switched to a Mac. I’m OK with almost all the shortcut but I missed one crutial one that I did’t find using Google.
On a PC when we use Shift + MMB, it allow you to move only on the x, y axis of the current 3D view. But that’s not working on a Mac…
Of course I had different tries like CMD+shift+MMB or Alt+Shift+MMB and even Cmd+Alt+Shift+MMB 
Does someone has a solution for that ?
Thxs in advance.
Just found it!
If someone got stuck one day, itùs Shift+4 for going left.
Replace 4 by 2, 6, or 8 to respectively go down, right or up.
I use both PC’s and Macs daily with Blender and both have that Shift-MMB function. Are you sure your mac is using your mouse properly? It might be thinking the MMB is a different button or something. Or OSX has that button tied to a desktop function like Exposé or something.
Indeed, when I push the MMB (with or without Shift), the Mac screen is showing the calculator, calandar, time and weather!
Searching how to remove that…
In the preferences pane for your mouse change the middle mouse to I believe its called button 3. You currently have it set to show the dashboard.
Richard
Thanks Richard, I already looked at that and there is no options to be checked for the third button.
Only options available are:
Digging there, I found in the keyboard shortcut menu that the key F12 call the dashboard. That dashboard is been called my MMB too…
Ah, you’re not using an Apple mouse. I’ve tried with a couple of other mice and everything still works ok, though I can’t see where you assign the mouse button options.
Richard
Hum… Interesting thread…
I use a Logitech Revolution and NEVER could have the scroll wheel to have ANY “button function” whatshowever!..
Still can Blender while renouncing that MMB.
Yet, if i could… would be quite glad…
I’ve only been able to change the middle mouse button assignment using the mouse preferences for an Apple mighty mouse. There may be specific mac preferences for 3rd party mice.
Richard
Aaaaargh!!! That was it…! :mad: Why does it look so obvious when you finally have the solution in front of your eyes ? Thank you Richard, your screenshot and comment were very helpfull
The problem was that I was not using my Apple single button anymore (Using a basic Logitech instead). So, the mouse preferences doesn’t look the same at all. For changing that, I had to replug the original Apple single button which showed a mouse preferences screen as the one Richard shown. After that it’s easy to make the changes and replug the Logitech mouse!
Again, thank you Richard… I honnestly started to get nervous of seeing that dashboard hundred times a day
As this thread became more “Mac” orienterd topic that a Blender subject.
Let me correct this one by asking an other “Mac oriented question for Blender” 
On Mac, the Python console doesn’t appear when you start up Blender. After searching, I’ve red that it’s suggested to work directly on the Python IDLE. Ok. But then, code like :
import Blender
doesn’t work!
Just in case, there is no file named “Blender.py” on the computer :o
The question now is how to detect eventual errors ?