I cannot protect all locked cells in Excel 2013.

My workbook has 7 sheets. After doing the following, a few text cells remain unlocked.

One worksheet at a time...
1) locked all cells

2) highlighted the few input cells that should remain unlocked

3) protected the sheet

4) after doing the above in each worksheet, i protected the entire workbook.

Most everything protected just fine. A few text fields - which remained locked - were not really locked, and could be altered for no apparent reason.