[lubuntu] Stubborn Firefox tries to open caja instead of pcmanfm and caja crashes

Hello

As I have stated in another post ( http://ubuntuforums.org/showthread.php?t=2327401 ), I have installed mate-core in my notebook with Lubuntu, to have both mate and lxde interfaces. A minor issue which was easy to solve was many shortcuts created, which I just needed to delete using pcmanfm, but one particular thing is being harder to: Firefox tries to open caja instead of pcmanfm when using lxde interface, when opening the folder where a downloaded file is.

Opening caja in mate interface is the intended result, but opening caja in lxde is not. In truth, this is terrible, because it freezes Firefox. To solve, I have to open terminal and open caja. Once opened, Firefox opens the folder and retus. Purging caja makes Firefox use pcmanfm again, but using pcmanfm for mate desktop looked terrible.

About caja crashes: when changing the options to see hidden files, if there are enough hidden files in the folder I am looking (to my notebook 2 images are enough already) caja crashes. As if it had to load all the properties at once and it crashed due to excessive demand on the computer.

I will try to add more information later.

Thank you