[Exim] "-4.8" is not a number

Hail all

I have bee hacking around trying to get some sort of spam rejection score
level set up but i am stumped at this error message with exim 4.24 and
spamassassin (spamd/spamc) 2.6.0.

2003-12-06 11:08:32 1ASaIY-0000Pt-8n <david@???>: spamcheck
transport output: 2003-12-06 11:08:32 1ASaIZ-0000Px-3e failed to expand
condition "${if and { { def:h_X-Spam-Flag: } { eq {$header_X-Spam-Flag:}
{YES} } { eq {$local_part} {david} } { >{$header_X-Spam-Score:}{6}}} {1}
{0} }" for spamcheck_is_spam_reject router: "-4.8" is not a number

I added the x-spam-score header with this in my spamassassin pref file
add_header Spam _HITS_

I notice the 4.8 si surrounded by 's does this mean exim is convinced it is a
strong.. because its negative.. because its non-integer.

Thanks in advance.

- --
David Leggett
david@???
http://www.asguard.org.uk
http://www.site-control.org
Get my public GPG key from http://www.asguard.org.uk/~david/david.asc
Fingerprint: 432E 4EAD E1E5 26BB 29EB 47FA CBDE AB17 0D23 C76B