Sudoku Players' Forum (clone)

I purchased and installed Sudoku yesterday. When I open a 9x9 game the vetical grid lines between the 2nd and 3rd, 4th and 5th, and 8th and 9th cells (ref top row) are missing on the monitor. The complete grid prints when I print a game. I've uninstalled and reloaded Sudoku, but the problem persists. Any suggestions how to fix

Try hitting F2 and playing with the line weights - might help

Thanks Shazbot. Your suggestion worked.