Hi,
There are a few things here:
First there should be a button to toggle on/off the snap to grid:
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Next you can open the Drawing Aids palette from the Windows menu. Here you can adjust the grid and turn on/off aids:
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If you go to the Layout palette you can st the y coordinates of the objects and the margins:
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If the objects have different borders or margins, then you will need to adjust the y coordinates. You can also just type in a new y coordinate to 0.0001in accuracy.
Hope that helps,
Niall