vsftpd recursive directory remove failed

[lessless]

Hello i'm using vsftpd to allow user upload files in webserver directory with umask=020

here is the full config:

/etc/vsftpd/vsftpd.conf
anonymous_enable=NO
local_enable=YES
write_enable=YES
dirlist_enable=YES
download_enable=YES
vsftpd_log_file=/var/log/vsftpd.log
pasv_enable=YES
local_umask=022
dirmessage_enable=YES
xferlog_enable=YES
connect_from_port_20=YES
xferlog_file=/var/log/vsftpd.log
nopriv_user=ftp
chroot_local_user=YES
ls_recurse_enable=YES
listen=YES
user_config_dir=/etc/vsftpd/users
log_ftp_protocol=YES


# cat /etc/vsftpd/users/dreamlair (the uploader account)
local_umask=020
#chown_uploads=YES
log_ftp_protocol=YES


now, he can not remove particular dirs with no reason via ftp, but can do use ssh, while have all sufficient permissions:

drwxr-xrwx 3 dreamlair users 80 Апр 1 12:00 php

Fri Apr 1 12:40:24 2011 [pid 3] [dreamlair] FTP response: Client "192.168.51.2", "250 Directory successfully changed."
Fri Apr 1 12:40:24 2011 [pid 3] [dreamlair] FTP command: Client "192.168.51.2", "RMD php"
Fri Apr 1 12:40:24 2011 [pid 3] [dreamlair] FTP response: Client "192.168.51.2", "550 Remove directory operation failed."

also i cannot strace vsftpd, because of fork and -f didnt help. how can i resolve this stuff ?
it do not remove some directories, but files locate in this directories removes ok