<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by sunil:
you guys have way too much time and are way too paranoid 
jokes aside I find that I really don't have the time to record every transaction (web or otherwise) in my life. </font>
It comes down to a matter of trust. I don't trust the system to not make material mistakes. Until I can get 200% assurance that all transactions are completely reliable, accurate, complete, and auditable at any time, I will continue to record these transactions.
I've seen quite a few system errors in person, and can not believe that even a simple database error will corrupt many transactions. It's always better to take a second to get the proof at the time of the transaction, than try to sweat it out when the one time that you need it and you don't have it.