Erroneously Getting "Item with Barcode Doesn't Exist" Error in Requests

Steps to Repro:

1. Log into snapshot-stable as diku_admin
2. Go to Inventory an find an item that is checked out (or get a barcode for an available item and check it out to someone)
3. Copy the barcode
4. Go to Requests
5. Click the new button to create a new request
6. Paste the barcode into the item field
7. Go down to the Requester field and click Requester lookup
8. This may result in some errors (see UIREQ-126 for details on that bug)
9. Close errors, if needed and select a requester
10. Save the request
11. Click new to create a second request
12. Paste the barcode into the item field
13. Go down to the Requester field and click Requester lookup
14. This may result in some errors (see UIREQ-126 for details on that bug)
15. Close errors, if needed and look at the item field

Expected: "Item with this barcode does not exist" error should not appear, as clearly the barcode does exist because I grabbed it out of Inventory

Actual: "Item with this barcode does not exist" appears

NOTE: I think this may only happen when you have already made one request for the item in question. It might also only happen after the requester bug (UIREQ-126) has surfaced.
Screencasts:

• https://www.screencast.com/t/qdpmW9Ow
• https://www.screencast.com/t/xz3FhhVw9QwQ