Did you try changing the video settings from the boot screen options? It sounds like you're fighting a video driver issue.

No i didnt change nothing what i need to change?

Ok, if PCLinuxOS is working (atleast the terminal), try configuring xorg yourself.

Run these commands in order if the previous one doesn't work: xorgcfg, xorgconfig

in the xprgcfg the pc stucked :S
maybe i will go buy a nVIDIA, which nVIDIA manufacture is best working with Linux?

ATI drivers support R500, is this your video chip?

the chipset is just "Ati" thats what it says

xorgcfg is an automated tool, which most of the time does suck But it always better to try the automated tool before indulging in hand-to-hand combat

Did you try xorgconfig? I am pretty sure you will be able to make it work somehow. A time will come when you will be asked for video drivers: chose "vesa" if nothing yields to you, my friend!

Btw, ATI drivers suck! If you are planning to buy a new one, nVidia would be a good choice. If you don't want exceptionally good drivers, chose intel or via. They have open source drivers.

ATI works fine enough as long as you use the proprietary driver. Running anything from the X1000 series with the open-source driver is a lot less fun, though. I got so fed up with it that I ended up buying an nvidia card instead.

Anyway, this trick should work: if you find yourself in front of a terminal (black screen with a prompt), enter "root" for user and your root password. Then type:
cd /etc/X11
cp xorg.conf xorg.conf.bak
vi xorg.conf
This should open xorg.conf in the vi editor, which is a real pain in the *** to use if you have never done so before... Just scroll down (use the arrows on your keyboard) until you come across the "Driver" section and replace the driver value (probably "ati") with "vesa". In vi, you have to press i before you can start typing and you have to type ESC to get back to read-only mode.
When you are done - make sure you press ESC first - type :wq and Enter.
type this:
reboot now
and see whether things work better.

You'd better install the proprietary driver as soon as possible. Vesa works but that's about it.

By the way, one possible reason that it worked with Knoppix is that Knoppix may already have the radeonhd driver (the new open source driver for ATI x1000 cards) while most distros haven't. And don't worry if you can't find the xorgconf, xcfg etc. commands - most distros have abandoned them.

well its a problem cuz i was about to store some money to by an nVIDIA, just asked if any of manufactures is not working with linux or something

seems it wont work if i wont buy a new gfx?
or should i wait for ubuntu 8 to release? maybe it will support it?

This is not a distro that supports your hardware. Most of hardware is supported by kernel. With some exceptions like Xorg ATI driver. Which you neglect to install, I understand?

Look, pal. It's actually real easy. First you run lspci -v to see what you have there. If this does not help read documentation what came with your card, or open up your box and look at that GPU. Then you search Google and you'll find plenty of information like this. At this point you say Ahaa! And install ATI driver. Clear as mud, isn't it?
Of course, people are different. If you do not like Ahaa! variant you can always resort to different hardware or different OS or ... it's up to you.

to install the driver i have to run the live cd...how to install since i cant run the cd?

But you said you can boot through PCLinuxOS and Knoppix.

yeah, but what about ubuntu that is lagging in the stucking boot scripts ?