Some applications have normal icon in grid view, but have "gray gearwheel " in category view and search results

Is it because you had just installed the icons before slingshot/your machine was restarted?

No, these apps were installed a long time ago, so the pc was restarted a lot of times since.

I've got a similar issue with Desura.

This is after a system restart, open slingshot:
http://i.imgur.com/hMQ3V.png
- icons as expected

Open slingshot and type to search:
http://i.imgur.com/44Hkl.png
- icons revert to generic app icon

Maybe it would be helpful if you attached a .desktop or two that are not working to this bug. They are located in /usr/share/applications

I'm particularly interested in the contents of the Desura .desktop

Desura doesn't appear in that folder - maybe because it runs from my download folder? (doesn't create icon issues in Gnome Shell, though)

Desura:
#!/usr/bin/env xdg-open
[Desktop Entry]
Version=1.0
Type=Application
Name=Desura
GenericName=Game Manager
Comment=Download and play the best games
Exec=/home/brian/Downloads/desura/desura %U
TryExec=/home/brian/Downloads/desura/bin/desura
Path=/home/brian/Downloads/desura
MimeType=x-scheme-handler/desura;
Icon=/home/brian/Downloads/desura/data/desura.png
Terminal=false
Categories=Game;
StartupNotify=false

Jupiter (same issue):
[Desktop Entry]
Name=Jupiter
Comment=Desktop Management Applet
Icon=/usr/share/pixmaps/jupiter/jupiter.png
Exec=/usr/bin/jupiter
Terminal=false
Type=Application
Categories=GNOME;GTK;System;

This doesn't happen in the Nov. 1. build, proper icons both in app overview and in filtered results. All good!

Still happens to Skype, as of Slingshot version 0.7+r297-0+pkg15+r1~precise1
The icon entry is: "Icon=skype.png"

I need some people to test the attached branch by tigrang and confirm that it fixes the issue. Thank you.

If anyone one else wants to test, here is a test .desktop file you can try https://gist.github.com/tigrang/6312102/raw/09b075acc4e6f38e5eef35cf311b0664b8ce9573/test.desktop

In Grid view, the icon for "Testing Bug 1072036" will show. When you search "Test" it will not show.

After the patch, it should work in both views.