Spell-checking Protected Documents

I create forms in Excel at work for others to use as templates, and I use the Sheet Protection feature to restrict editing. The problem is that when the sheet protection is on, the cells that aren't restricted cannot be spell-checked. That feature is grayed out. The font size can't be changed either. That doesn't make any sense. If I identify certain cells as "unlocked" so that people can type in them, why shouldn't they be able to spell-check them?

Please help.