I have run into this problem many times and have communicated it to Symantec at least once. The best solution I have found is to use a Merge HTML component, then just before creating the file use the Convert HTML to Text component. Also, when using the Merge HTML component, to assure all of your carriage returns will stay when appending a dynamic number of times to the same variable, you should click "Source" at the bottom, then "OK".
Obviously not the way it was intended to be used but its the only solution I have found that will dynamically append information and keep the formatting in tact.