Most often caused by hitting the F8 key and putting yourself into "Extended
Mode".
If you see EXT on status bar hit F8 again to clear.
Another fix can be tapping, quite vigorously, the wheel on your wheelie-mouse a
few times.
Gord Dibben MS Excel MVP
>I'm typing in a spreadsheet but now that i'm clicking on one particular cell
>a whole range of cells become active. What am I doing wrong?