SSIS: Why do columns become misaligned when importing flat files?

Question

Hi All
I am stumped with the following.
When I try to load a fixed length flat file into a table, the first few thousand records load correctly but then the columns start going out of sync.
Visually it looks like the data is drifting off to the right. Below is what the table looks like when the load completes:
Col1    Col2    Col3    Col4
1        1         1         1
1        1         1         1
  1        1         1         1
   1        1         1         1
    1        1         1         1
      1        1         1         1
        1        1         1         1
Additional info:
1. The file has 400 000 records.
2. The first few thousand records load OK.
3. Source file is a flat file, fixed length, no delimeters.
4. All rows are same length, with LFCR.
I tried using a script task to check with C# if all rows are the same length and has the same line terminator, and could  not pick up anything out of the ordinary.
What could be the cause?

Answer 1

Thank you for the reply.
I discovered the source of the problem, but still don't understand how to solve it.
There is one extra character in one of the columns every few thousand lines. This is the character: �
I don't understand why all the rows following a corrupt row is shifted by one character and not just the effected row?
Secondly, via a script task, SSIS indicates that the length of the row is still the same, despite the extra character. Is it possible that SSIS does not recognize this character and this is what is causing all columns to shift / mis-align?