Guys, please, somebody help me with this, What do I have to do?
The only thing that happen is that appears the property window (the happy monke window), and when I click OK button, baaaam, it just dissapear.
I will really appreciate your help.
Thanks.
What test or program are you running? What OS/platform? What videocard?
And, you can try the webstarts on the mainpage, see if these work.
Ok, I have 128MB in RAM, a 900MHZ CPU, with a 8MBvideo card caps.; I know this is going to sound weird, but a classmate has a lamest machine and it runs!, So.....I don
A friend of me had the same problem. After hier installed the new ATI drivers it works.
Maybe it's a problem of your current opengl drivers.
Like madlion says, try updating your drivers. But "8MBvideo card" sounds very old. Your card has to support OpenGL/LWJGL for running jME. You can try to see if you can get the demos on this page to work: http://lwjgl.org/demos.php
Ok, guys, here
Well it was a short and glorious career 
How old the PC is shouldn't matter that much. (I've used jME on a 800 mhz PC for many months). But the videocard is very important. Like I said, you could try the LWJGL demos on the link I gave (it's only a few clicks). If they fail, then it's not a jME bug or something, but a problem with your videocard. But yes, it's very unlikely they will work.
Keep in mind though, a new videocard capable or running jME wouldn't have to cost more than 50$ or so, less even.