Hi Hayashi,
the password sent in the email should be correct in all cases. There were a few issues related to srmsus_selfreg and passwords, please check the following notes:
2040115
2029492
1703096
1580573
If any of these is missing in your release please implement it and recheck.
You can resend the email containing registration information from transaction BBP_SUS_BP_ADM under 'Notification for New Business Partner'.
regards
Zoltan