Error removing module

[Stanley.Miao]

OS: ubuntu 10.04 server 64bit
kernel: 3.1.4+ (built from source code)
systemtap: the latest version.( I just git clone the source code)
elfutils: 0.153

./configure --with-elfutils=/home/stanley/elfutils-0.153 --prefix=/usr
make
sudo make install

$ sudo stap -e 'probe begin {log("hello world") exit()}'
hello world
Error removing module 'stap_9d638c974730532719dbb6696e35b4e2_748':
Device or resource busy.
WARNING: /usr/bin/staprun exited with status: 1
Pass 5: run failed.  Try again with another '--vp 00001' option.

$ dmesg|tail
[ 1323.937036] stap_3cb83415e3c3a2f147426e0154dbce86_748: systemtap:
1.8/0.153, base: ffffffffa0168000, memory:
20data/26text/3ctx/2058net/23alloc kb, probes: 1


Does anyone encounter the same problem with me?  How to resolve it ? Thanks.


Stanley