Just let me digress a moment to say that this is not true, and I'll appreciate no further assumptions like this. I'm not upset or anything, but I don't want that sort of image to be tossed around while I'm busy fixing bugs and developing features elsewhere in the code.
The issue here w/ PayPal is complex, and since I can't reproduce it it's hard for me to fix. None of the information provided so far has given me a good lead to track down the issue. Just so we're all clear on the issue, this is not a problem with Ubercart failing to recognize PayPal payment or complete an order. As was pointed out, orders are actually being completed. This is because we rely on the PayPal IPN payment to know when payment has actually been submitted, and when that happens we submit the order.
The real issue is whether or not a proper return address is being recognized. When this works properly, it is because the address PayPal sends you back to gets recognized by Drupal and through that it clears out the cart contents and sets the appropriate variable to send you to the checkout completion page. If this gets missed, then you will be sent back to the cart page because of the way Drupal is resolving the URL.
So, all this involves the way Drupal works... it defines "URLs" on the fly for each page load. If it can't find the exact one you request, it goes down the line until it finds the closest match. That's how you end up at the cart page. Because of these things, it seems to me that the thing about an attribute is coincidental and not the root issue. I'll look at the code and see if it's something to do with Workflow-ng, but there again I'm skeptical. It's an issue with the way the URLs are being defined, and I don't really know how to best get to the bottom of it. Just know that it's in the issue queue and has been for a while, there just hasn't been a readily available fix or investigation method.
Joined: 08/07/2007