I don't have a solution but I have had this happen in my overview panels. I get everything positioned to the pixel but when I click on an item, if I am not careful and the mouse moves slightly, the item will move. They could add a "Lock/Unlock Position" check box in the settings or even directly in the right-click context menu. If you want to move multiple items, select them by left-click and dragging, then right-click to access the Lock/Unlock check box. This would be an extra step when you do want to move an item.

I wish they would also add a position coordinate Global Offset command. After selecting multiple or all items in an overview page, right-click and select Global Offset. Type in an x and y offset coordinate. The command adds the x and y offset coordinate value to every selected item’s current x and y coordinates. This would be very useful when you have multiple displays, add a display, or rearrange displays, and want to quickly move an overview page to a different display.

I think (and hope) both of these things would be rather simple to add to Aquasuite and I hope the programmers will consider them.