[CentOS] Crash when open a terminal after upgrading from centos5.9 to 5.11

Dear all,
I  had installed Centos 5.9 in my x86_64 system and I installed update yesterday. Just now after I initiated the system, I found it has been upgraded to centos 5.11. But the bad thing is now I cannot open a terminal. When I try to open a terminal, it just gives out a bug buddy  window : 
"The information about the crash has been successfully collected. Please provide some background about what you were doing when the application crashed..."
Could anyone help me about this? Thanks in advance.

Yeping Sun