Excel will not let me click into cells or incorrect cell is selected randomly

Adjusting the width of any column, or turning off (then optionally back on) freeze panes, will un-stick Excel and let the correct cell be selected, and/or enable cell editing.  PITA and surely something the brainiacs at the Excel team could figure out.

(And while tinkering, how about

a) fixing Excel so that it never clears the clipboard of data the user selects and copies.  Another royal PITA.  Or at least explain why Excel feels it necessary to destroy the clipboard if a minor edit to some part of a sheet was made, not affecting the source data.

b) fix normal formula text boxes where it is impossible to click, select and delete text without hitting F2. Some days.  Others it works like a normal text box.  It is a crapshoot whether the text box you're presented with is going to behave like a proper text field, or a wonky excel-rule text box when unnecessary.)