I believe this is a product issue that is currently being worked on. Some of the asset fields were not properly indexed for some reason. If you contact support, they can open a case for you and link it to the product issue so you will be notified when it is corrected. I believe this fix is actually slated for the Nov/Dec timeframe and includes a few other index fixes as well like owner, asset tag and a few others.
Great news!. Thanks Cris.