Shaded merge fields

Hello there..I have developed a Form letter with merge fields, and that data
source is an excel document.

However, when the documents are merged and printed out, some of the merge
fields are shaded, and some are not (the printing is shaded). I do not want
these fields to be shaded. How do I stop this from happening.

Also, when I print out the document, any "blank" fields (eg the address
line) are deleted, but when someone else does it on their computer, the
blank field leaves a blank line. Do you know why this happens? Is it an
option?

Any help would be appreciated.

Cheers
Caroline