I used to create text files for importing data into another program (MYOB)
without any problems, using Vs 2002.
It seems (although I can't prove the exact time) that problems started when
I upgraded to Vs2007.
Now, using Vs2007, when I use the same Excel workbook and create the
Tab-delimited txt file from Excel and import that into the other program, I
get problems.
eg some fields are treated as -'ve when they should be +'ve, (although that
doesn't really explain the problem).

When I export the data to a text file from the other (MYOB) program and
import it straight back, there are no problems.
However, if I open that same text file in Excel 2007, and then save it as a
text file again (without making any changes!), the problems occur.
(When I save as a text file from Excel it warns about incompatable features,
etc., which is to be expected, and I choose Yes.)

Rob