String replacement in V29.0.00

Hi,
Before updating to the newest version I as able to use string replacement successfully to replace two fields. Now, if I want to add a new string, no search results pop up under the “Original String” field when I type, so even if I type in there and submit a new replacement, it does not affect any change.
In the Edit Markbook Column there is a field “Type” under Basic information. I would like to replace “Exam” with “Half Term”.
It would be great if someone could help.
Thanks,