When you insert a notice and for any reason the position of associated cell is
changed, the notice stays at the former position and therefore sometimes it is
not possible to read it.

For example:
- create a new calc worksheet
- go to cell A150
- insert a notice (Insert->Notice)
- insert some dummy text into the yellow notice field
- leave the notice field (there should be a litte red dot at the upper-right
corner of the cell)
- move the mouse-arrow over the cell, the notice is shown, everything OK so far
- now select a large number of rows above the cell with the notice, e.g. rows 10-140
- while the rows are selected, press F12 to group them
- click the '+' icon on the left side to fold the grouped rows
- now move the mouse cursor over the cell with the notice
- the notice is still at the old position, which is for this example about line 277

IMO the position of the notice should depend on the position of the associated cell.