In Word 97 and before, one could set the sentence length to a value that was
suitable. In Word 2003, the default is something like 60 words which is just
too long for my purposes. Worse, if you have both Word 97 and Word 2003 on
your system, Word 2003 will also reset your 97 grammar style checking to 60
words and you are not able to reset it to 25 words per sentence.

Work-around 1 that I do not care for:
Install WordPerfect. Do the style editing in WordPerfect and go back to Word
2003.
Work-around 2 that I do not care for either:
Install Office 2003 without Word 2003. Install Word 2000 or Word 97.