Dash gives unexpected file results

[TenLeftFingers]

TO REPRODUCE:
Create these two files in your home directory using the touch command in a terminal (ie, the files must not have been opened by a desktop applicaiton).

touch Alien\[1979\].txt
touch Alien\ Resurrection\ \[1997\].txt

Open the Dash and type the text "alien" without the quotes. You should not see these text files in any results because we haven't opened them yet. This is expected behaviour (if not desired).

Now, open the first file by double-clicking in Nautilus. Text Editor will open and display the empty text file. Close the application again.

Open the dash (Super + f for file search) and type "alien". You should see our first text file in the results - so far so good.

Close the dash and open the second text file in Text Editor. It will show an empty file. Close the application.

PROBLEM: Open the dash again (Super + f) and type "alien". Now only Alien Resurrection shows in the dash, the first file is ignored.

Still in the dash, type "alien[". Now our first file appears. Delete the entire search phrase and type "alien" again. The same file appears (Alien[1979[.txt). Close the dash and reopen and type "alien" again, now the other file appears (Alien Resurrection).

EXPECTED BEHAVIOUR: I expect the second file to simply be appended to the search results, not to replace previous valid results. I also expect changing the text back to the original string to return the results that that string gave previously. But in this case string results seem sensitive to their relation to prior searches.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity 5.18.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-39.62-generic-pae 3.2.39
Uname: Linux 3.2.0-39-generic-pae i686
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: i386
CompizPlugins: [core,composite,opengl,decor,regex,gnomecompat,snap,compiztoolbox,move,grid,mousepoll,vpswitch,place,animation,resize,imgpng,unitymtgrabhandles,session,expo,workarounds,ezoom,wall,fade,scale,unityshell]
Date: Thu Mar 28 17:11:12 2013
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta i386 (20120328)
MarkForUpload: True
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Lucas Benninger (lucas8060-deactivatedaccount)]

This also affects Unity 6.6.0:

Package details
unity:
  Installed: 6.12.0daily13.03.25.1-0ubuntu1
  Candidate: 6.12.0daily13.03.25.1-0ubuntu1
  Version table:
 *** 6.12.0daily13.03.25.1-0ubuntu1 0
        500 http://archive.ubuntu.com/ubuntu/ raring/main amd64 Packages
        100 /var/lib/dpkg/status