Are you talking about the SMCorders table that isn't being written into?
In order to debug this we are going to have to figure out how to debug it. That means reproducing the problem. I can probably update the pp_confirm page and log any access to the page so that when another one fails we can at least reproduce it.
What is the field size you are using for the SMCorderPAYPALRESP column? Maybe it is running into a size limit?