Well, the trace shows that a reference is being made to the clipboard page CustResPage.pxResults(1). I'm guessing that either the clipboard page is not there, or it contains invalid information.
There's not enough info to help me look further. If it is one of your pages (as I suspect), perhaps you can determine from knowledge of your own application what this page is used for?
If you can narrow this down enough, you may want to Trace that part of your application that references this page, in particular using the pxResults(1) array. Even looking at a success case may provide a clue as to what might be going wrong; you might be able to make your code a bit more defensive. Or, you might add some diagnostics to help further the investigation.