It’s happened to me twice today. First I bought a nice MF trinket at almost 7G, Vallog’s Demise, upgraded it with an exquisite opal jewel, realized I didn’t need it and then couldn’t relist it, can’t place it in the guild bank either. I never wore it, and it has not yet been soulbound, so I should be able to resell it. It would be nice if this could be fixed so I could reclaim some of that gold.
This evening, I crafted a level 10 malign crude staff for a guildy starting a new necro toon, upgraded it with a pebble (The condition damage one). I couldn’t mail the item to him and, like the above trinket, couldn’t even place it in the guild bank. I had to craft another for him, send him the items and let him apply the upgrade himself.
It seems upgrading an item mistakingly binds the item to the player, even if it has not yet been soulbound and even if the items do not soulbind, such as a level 10 staff.

Since this is not longer a bug report, we proceed to close the thread now.