[Spambayes] Tough to classify

[David Shaw]

I placed an order with Amazon today.  I got a TiVo and a Java book.  
The order confirmation came back unsure, with 123 clues pointing both 
ways, and probability as follows:

*H* 0.981571864474	
*S*	0.56420331545	

This message is obviously ham to a human, but here are some of the 
higher spam clues:

find,	0.908163265306	
day?	0.908163265306	
$5,000.	0.908163265306	
20,	0.908163265306	
url:help	0.908163265306	
telephone:	0.934782608696	
order:	0.934782608696	
buy	0.942237128563	
saver	0.949438202247	
seller	0.96511627907	
online,	0.983271375465	
ordering	0.987106017192	
dollar	0.987106017192	
grand	0.988431876607	
shopping	0.992091388401	
tax	0.994699646643	
subject:with	0.99504950495	
subject:Your	0.997366881217


What can be done in a case like this?  I don't order from amazon that 
often (maybe 4 times a year), but amazon itself is a ham clue:

url:amazon	0.155172413793

I feel like spambayes has enough clues to know this is ham, it's just a 
question of calculating the probability in such a way as to recognize 
it.  I would be interesting in any thoughts on this.