I've tried it with both 1.0.4 and 1.1a3.
If the message with attachement exceeds ~2Mb spambayes
messes something up and the outlook reports an error
Task '217.10.144.98 - Receiving' reported error
(0x800CCC0F) : 'The connection to the server was
interrupted. If this problem continues, contact your
server administrator or Internet service provider
(ISP).'
Seems like spambayes is reporting message size bigger
than it is.