This thread refers to a problem with having the UPC having been separated out in v2007. It's a good question so I decided to expand on it in this Latest Release forum....

Here's what I see in our account:

1) For items that were entered before the v2007 upgrade, the Item dropdown on the sales order form still includes the concatenated UPC and item name.  For a new (test) item created after the upgrade, it no longer includes the UPC - just the item name + display name (why both, btw?) 
Edit/correction: I just noticed that the items that were created before the upgrade were actually changed at the time of upgrade (not by us, that is) so that the UPC code is in both fields (item name and UPC code) - that's why they appear to be different than the item created after the upgrade.  So really what's happening is that the UPC code isn't used in the dropdowns at all.  It now contains just the item name + display name.