Unlocked cells not available when sheet is protected.

I have a little issue with my spreadsheet. It's a simple data entry with VBA coding. Including the hidden 'validation' sheet there are 2 sheets.
There is some VBA script run on opening the spreadsheet, including freezing the top line.

Problem is, I have the worksheet protected so that users can only enter details into selected cells. Users can only select the cells that are unlocked however users can only select down to row 5 yet when checked, cells below row 5 are not selected to be locked.

I don't know if it has anything to do with the VBAs I'm using or if it's an issue with Excel / spreadsheet but I'm hoping someone can resolve this for me (or at least give me some idea's)

I have attached the sheet so you can take a look for yourselves.


Thanks in advance.