Fence post error in two-column table formatting loop

[SlurrerOfSpeech]

I'm writing a class to format console output and the trickiest method in this class so far is the one for printing a table. I'm having it act like an HTML table in how text fits

        public static void PrintTable ( string[][] cells )
        {
            // Outputs content in cells matrix like 

            // =========================================
            //  cells[0][0]   | cells[0][1]
            // -----------------------------------------
            //  cells[1][0]   | cells[1][1]
            // -----------------------------------------
            //  cells[2][0]   | cells[2][1]
            //                .
            //                .
            // -----------------------------------------
            //  cells[n-1][0] | cells[n-1][1]
            //  ========================================

            // Each cell must be able to hold at least 1 character inside 
            // 1 space of padding on the left and right

            int linelen = OutputFormatter.OutputMaxLength; // copy of width (in characters) of lines being formatted
            // Calculate widths of columns 1 and 2 (excluding the single space of padding on the 
            // left and right side of each):
            int w1 = Math.Min(cells.Max(c => c[0].Length), linelen - 6);
            int w2 = linelen - w1 - 5;
            OutputFormatter.PrintChars('-'); // prints a line of equals signs for the top border of the table
           
            // print out rows:
            foreach ( string[] row in cells )
            {
                // Make the strings corresponding to the first and second column have equal
                // length by adding whitespace to the end of the shorter one:
                String padding = new String(' ', Math.Abs(row[0].Length - row[1].Length));
                if ( row[0].Length > row[1].Length ) row[1] += padding;
                else row[0] += padding;

                // Print out content of row
                int i = 0, j = 0, n = row[0].Length - Math.Max(w1,w2);
                for ( ; i < n && j < n; i += w1, j += w2 )
                {
                    Console.WriteLine(" {0} | {1} ",
                                       row[0].Substring(i,w1),
                                       row[1].Substring(j,w2));
                }
                Console.WriteLine(" {0} | {1} ",
                                   row[0].Substring(i,row[0].Length - i),
                                   row[1].Substring(j,row[1].Length - j));                                OutputFormatter.PrintChars('-'); // prints a line of dashes to separate rows
            }

        }

It's almost correct except for the fence post

                Console.WriteLine(" {0} | {1} ",
                                   row[0].Substring(i,row[0].Length - i),
                                   row[1].Substring(j,row[1].Length - j));

For example, when I test it with the string

        private static readonly string[][] _instructs = new string[][] {
                                                                         new string[] {"CompareLastTwo","Shows difference between friends lists of last two Facebook data files in repository"},
                                                                         new string[] {"AddFriendList <DataFolderPath>", "blah blah blah"}
                                                                       };

here's what it ends up looking like:

Where's the flaw that is causing that? I'm trying to make this as compact, elegant, efficient and readable as possible, but it's proving difficult.

 

[.Scott]

The width of row[0].Substring(i,w1) is w1.
The width of row[0].Substring(i,row[0].Length - i) can be less than w1.

 

[Svein]

When I did something similar way back when, I ended up by creating a string of length 80 (the width of the console), filling it with spaces, inserting the substrings (sprintf()) and at the end inserting the "fence post" at the correct place. Then printing the complete string.

 

[.Scott]

Do you realize that the row(0) string needs more padding? In needs to be padded out to a length that is a multiple of w1.