Could not create an Appender. (Class 'org.apache.log4j.RollingFileAppender' not found)

hello,all :
    My log4cxx version is 0.9.7,and when i linked my program with dynamic 
library, it worked fine.
    But i changed to linking with static log4cxx, i get the info listed below:
        Could not create an Appender. Reported error follows.
        Class 'org.apache.log4j.RollingFileAppender' not found

        I googled and got some advise below:
        1/ by not using default configuration and doing an explicit 
configuration sometime after all the static initializers have completed  . (But 
I don't know how)
        2/ try using 0.9.8 (but some user of 0.9.8 got the same bug too, and i 
am trying ,too)

        any good suggestion?
        thanks in advance