SPListItem update yields ItemUpdated/ing Numbering Scheme not found

Question

I've written a console app that searches items in a SP document library (MOSS 2007) for a specific condition and updates the value in a column for each item that meets the criterion. I run the console app as a domain/SP admin and on the front-end SP server, so there is no question of security, rights, etc. The code in question is as follows:

 item["some column"] = "some value";
 item.Update();   

In my test environment, the above code works perfectly. But in production, it sometimes appears to work properly but more frequently spits out extra output that looks something like this:

1 2/19/2012 10:23:47 AM ItemUpdating http://server/sites/web/Shared Documents/Document01.pdf > http://server/sites/web/Shared Documents/Document01.pdf
1 2/19/2012 10:23:47 AM ItemUpdating SetID: Key=shared documents/Document01.pdf value=
<?xml version="1.0" encoding="utf-16"?>
    <udn xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
        <id>0002871</id>
        <time>634652438271779415</time>
        <move>false</move>
        <movefinished>false</movefinished>
    </udn>
10 2/19/2012 10:23:47 AM ItemUpdated SetValue: 0002326

Examining the item's column value, I can see the column value has been updated. But all this output is making me wonder if there are any adverse side effects.