Thanks.
Now I am using another version "PCLinuxOS 2009.2". I don't want to use version 2010 because it's slow and my PC hardware configuration is not vary high.
I meet another problem. When I install a arm-linux toolchain and run command "source /etc/profile", I found a problem: bash: TMOUT: readonly variable.
I don't know where the "TMOUT" is defined. When I was using PCLinuxOS 2007, I also met this problem but I found "TMOUT" defined in /etc/sysconfig/msec and fixed it. But now I can't find this file in version "2009.2".