Icon problem with thunar
 

hello, I have installed slack12 in my pc and I'm using the XFCE desktop enviroment, but in the thunar file manager all file icons looks exactly equal, I tried to changing the icon theme or installing the "gnome icon theme" without any success yet

Have you looked under "User Interface" in the XFCE configuration menu? From there you can select what icon theme you want to use and make a few other changes. You might find something useful there.

I did a little digging, and apparently running xfce-mcs-manager does the trick - I tried on my system and it's fixed that exact problem, even though I use thunar in WindowMaker.