File search with partial file name doesn't work if there isn't wildcard "*" in the end. Otherwise it doesn't find the right file if there is even a single letter missing in the end. Partial search works for other Krunner plugings such as for recent files. Isn't that supposed to work for file search as well? I have set "Enable Nepomuk Semantic Desktop" and "Enable Nepomuk File Indexer" in KDE System Settings > Desktop search and set right types and locations at > Indexing. I've enabled "Nepomuk desktop search" and "Locations" Krunner plugins.

I've tried this with new user account, restarted krunner with "kquitapp krunner && kstart krunner", tried different file types and locations but same results. Using KDE 4.11.2 and openSUSE 13.1.

Yeah I can confirm this issue.
Moreover for me:
If you have a file called something.xls
typing this into krunner
something will return nothing
something* will return nothing
something.xl* will work.
something.xls will work.

Pretty ****.