Many of you may have noticed that the behavior of the SNAP command has changed in AutoCAD 2012.
In previous versions, the cursor used to be attracted to the grid even when no command was active.
In AutoCAD 2012, when SNAP is turned on, the cursor is attracted to the grid only when a command is active.
For those users who prefer the "old style" Snap, a new variable called SNAPGRIDLEGACY was introduced in SP1 for AutoCAD 2012.
A value of 0 is the default setting and will keep the new 2012 Snap behavior (the cursor only snaps to the grid when a command is active)
If you prefer that the cursor snaps to the grid even if no command is active, set SNAPGRIDLEGACY to 1 and Snap will behave as in previous versions.