Why the grep result depends on folder path?

I meet a strange phenomenom when using grep on Solaris 10:

I try to use grep to find creat related DTrace probes. When in a folder (/data1/nan), it works OK:

bash-3.2# pwd
/data1/nan
bash-3.2# dtrace -l | grep creat*
   27 hotspot586         libjvm.so __1cHThreadsJcreate_vm6FpnOJavaVMInitArgs_pb_i_ vm-init-begin
   28 hotspot586         libjvm.so __1cHThreadsJcreate_vm6FpnOJavaVMInitArgs_pb_i_ vm-init-end
  574        fbt              aggr                   aggr_ioc_create entry
  575        fbt              aggr                   aggr_ioc_create return

While in another folder(/data1/nan/DTraceToolkit-0.99/Proc/), the grep can't find anything:

bash-3.2# cd /data1/nan/DTraceToolkit-0.99/Proc/
bash-3.2# pwd
/data1/nan/DTraceToolkit-0.99/Proc
bash-3.2# dtrace -l | grep creat*
bash-3.2#

Could anyone give any clue about this issue, thanks very much in advance!