Are you actually entering:

subject: wrote:

on a line in the keyword file, and this is not stopping an email with the subject for example of:

This is a test of wrote: keywords

If so, this email should have been blocked (we just double-checked...). Could you zip us the section of SpamFilter's logfile showing one of these emails coming in?

Don't think so... If you had:

subject:wrote:

this would have caught both subject lines:

this is a wrote: test
this is awrote: test


If you had:
subject: wrote:

this would only have caught the subject with the sequence [space]wrote:

this is a wrote: test

If there was not a [space]wrote: sequence this would not have triggered, for example this would not have been caught:

this is awrote: test