unable_to_chdir_to_maildir

[Vince]

please help i got this error in my qmail system,

Jun 22 18:30:02 qmail qmail: 961669802.819169 starting delivery 15: msg
95447 to local [EMAIL PROTECTED]
Jun 22 18:30:02 qmail qmail: 961669802.820265 status: local 1/10 remote 0/20
Jun 22 18:30:02 qmail qmail: 961669802.894011 delivery 15: deferral:
Unable_to_chdir_to_maildir._(#4.2.1)/
Jun 22 18:30:02 qmail qmail: 961669802.895107 status: local 0/10 remote 0/20

what is my mistake here? 

thank you!