Error when copying and pasting fields with validation

I am having the strangest of issues.

I have created a daily operating room schedule in which each time slot has a drop down box for the Doctor doing the procedure and the Group of doctors from which he/she came.

It is a yearly schedule with each day of each month duplicated on a tab for that month - the same daily schedule for each.

I have been able to duplicate each day right up until the 25th of the month in which I attempt to save the spreadsheet and am given an error stating it can not save some of the data, though the data appears to be intact (the validation drop down lists)

Upon closing and reopening the spreadsheet, all of the cells that contain validation including and after the 25th of the month are simply gone.

I have attempted to attach a copy of the file but I keep encountering an error with the database.

Any help would be greatly appreciated as I am very near to being bald

Zip file with xls file has been added