Pivot not grouping properly

[livifivil]

This is the most infuriating problem. I have been keeping this same grid for years. For whatever reason, I got some new data for 5/12/13 and now the pivot table is not grouping it properly. Basically, there are 4 column headers. Either X, C, O or R. If you pick any of the other dates, everything is fine. If you add in the 13th, instead of 4 columns there are 8. There becomes 2 of each letter. I checked the formatting and everything looks uniform. I attached the grid. Any help would be appreciated, thanks in advance.