MailScanner/SA crash (regex limit?)

[ISP List]

Had my first MailScanner problem in quite a while this morning (well, it
isn't really MailScanner, I suspect it is SpamAssassin, or rather some Perl
limitation).  Error is as follows:

Quantifier in {,} bigger than 32766 before HERE mark in regex m/^45962\ \
Subject: (.{ << HERE 45953})/

MailScanner would croak after the above error, and ~7,000 messages backed
up in the few hours it was looping with this error.  I turned off
SpamAssassin checking, and things went through OK.  Suggestions as to ways
to prevent this from occuring in the future?  Why would MailScanner not
just bypass the message causing it to croak and move on to the next one?

--Mike