Log file could not record the address

[kiss351523]

Deall All:
the log file "tm1auditstore20111***.log" from Logging Directory,could not record the address of logged client PC,it just record:

<Commit ts="20120502034839" client="Test">
"144","Test","","User 'Test' successfully logged in from address ''."
</Commit>

what is that,why the address is null?

[kiss351523]

In the TM1.cfg file:
AuditLogOn=T
AuditLogMaxFileSize= 100 MB
AuditLogUpdateInterval=60


And my TM1's version is 10.1.
TKS!