Hi Henrik,
Yes and to flesh it out a bit, what I do when my members pay by paypal is to a) gather all the payment details and amounts.
b) create the transaction record and set a transaction status of "new"
c) send them to the Paypal site
d) on return, set the transaction status to "applied"
Doing this means you can create queries to find the transactions with a status of "new". This usually means either the user has cancelled the transaction whilst on the PayPal site or (more likely) they complete the transaction but then forget to click "return to Merchants site" and just close the browser.
in both scenarios, AwareIM has no way of knowing whether the user has completed or not, so the transaction is held in the "new" state and can be manually completed when the PayPal email notifications come through.
In my case, I have an "alerts" tab on the admin home screen which lists all the payment transactions with a staus of "New" (amongst other things)
later this year, I plan to revisit my PayPal stuff to see if I can fully implement IPN (instant Payment Notification) since there are a number of codes that PayPal can return that AwareIm cannot trap. such as a "hold" if a user pays by e-cheque , "Payment reversal" if a bank or Credit card declines or reverses a payment. "server Busy" if a payment cannot be processed in a reasonable time - there are several more.
anyway - hope thisnhas helped.