Penalty too low for non-formatting differences

Hello,

Trados applies a -1 penalty for matches with different formatting (say a missing tag). Unfortunately, a -1 penalty is also applied to matches with differ (slightly) in content. I regularly have segments of 20 to 40 words with 1 (important) word being different. These also get a -1 penalty.

The problem is that when I review my translation, there is no way to tell whether a 99 % match means a tag was missing or that a word was changed. By way of comparison: Wordfast Pro considers this as a 91 % match. Is there a way to increase the penalty for non-formatting differences? Thanks, Mark