[Assp-test] >50 points but not tagged as spam (one in maybe hundret emails)

[<kr...@gm...>]

Dec-12-12 00:36:26 98.16.151.147 <ls...@ro...> to:
admin@MYDOMAIN.org Message-Score: added 7 for bombSubjectRe: 'waiting
(7)', total score for this message is now 7;
Dec-12-12 00:36:26 [BombSubject] 98.16.151.147 <ls...@ro...>
to: admin@MYDOMAIN.org [scoring:7] -- bombSubjectRe: 'waiting (7)' --
[Your new intimate life is waiting for u];
Dec-12-12 00:36:26 98.16.151.147 <ls...@ro...> to:
admin@MYDOMAIN.org Message-Score: added 10 for Suspicious HELO:
'98.16.151.147', total score for this message is now 17;
Dec-12-12 00:36:26 [SuspiciousHelo] 98.16.151.147 <ls...@ro...>
to: admin@MYDOMAIN.org [scoring:10] -- Suspicious HELO:
'98.16.151.147' -- [Your new intimate life is waiting for u];
Dec-12-12 00:36:26 98.16.151.147 <ls...@ro...> to:
admin@MYDOMAIN.org Message-Score: added 50 for PTR invalid
'h147.151.16.98.dynamic.ip.windstream.net', total score for this
message is now 67;
Dec-12-12 00:36:26 [MessageOK] 98.16.151.147 <ls...@ro...> to:
admin@MYDOMAIN.org message ok [Your new intimate life is waiting for
u];
Dec-12-12 00:36:27 98.16.151.147 <ls...@ro...> to:
admin@MYDOMAIN.org finished message - received DATA size: 867 Byte -
sent DATA size: 1.36 kByte;
Dec-12-12 00:36:27 98.16.151.147 <ls...@ro...> to:
admin@MYDOMAIN.org disconnected (2 seconds);

>50 points but not tagged as spam (one in maybe hundret emails). Other 99 emails are tagged properly as spam. Seems like a bug, not configuration issue (?)
ASSP Version: 1.9.8(12336)
MessageScoringUpperLimit=50