Negative SA score reported in subject line

[Martin Vlach]

I have the following configuration set for MailScanner 4.78.17-1:

Required SpamAssassin Score	4
High SpamAssassin Score		8
Spam Modify Subject		start
Spam Subject Text			{Spam _SCORE_}

The problem:
negative scores are reported to users in their Subject Line. They see scores
-1 through -4.

I am fine with the scores themselves; the problem is that they are reported.
I assume that any scores below 4 should not modify the subject line.

I've searched many places (google, faqs, documentation), but can't find
anything.
I would like suggestions on the best approach to fix this problem for our
users.

Thx, Martin