Pogo Daily Sudoku Calendar

The calendar in Pogo Daily Sudoku lags when trying to go back to previous months and years, and when it finally allows you to go back, when you play one of the games it repeatedly pops up messages about "your progress couldn't be saved' and then it says you have to "restart game or quit game". What gives? This has been going on for a long time for me and it is annoying because I am trying to finish all the older Pogo Daily Sudoku puzzles. Please fix this!