Ubuntu – VSFTPD configuration problems with 12.04

So I upgraded my Ubuntu Server to 12.04 LTS today and now VSFTPD wont work. I think it is related to this VSFTPd stopped working after update

However, unlike the asker in that post, I am not getting any error messages. When I log on, I get

220 (vsFTPd 2.3.5)
331 Please specify the password.
Password: 
530 Login incorrect.
ftp: Login failed

I know the password is correct,and I have tried multiple users. vsftpd.log shows nothing other than:

Tue May  1 15:19:48 2012 [pid 2] CONNECT: Client "192.168.1.133"
Tue May  1 15:19:53 2012 [pid 1] [USERNAME] FAIL LOGIN: Client "192.168.1.133"

Syslog shows nothing. Here is my VSFTPD.conf (mostly default):

listen=YES
anonymous_enable=NO
local_enable=YES
check_shell=NO
write_enable=YES
local_umask=022
dirmessage_enable=YES
use_localtime=YES
xferlog_enable=YES
connect_from_port_20=YES
chroot_list_enable=YES
chroot_list_file=/etc/vsftpd.chroot_list
secure_chroot_dir=/var/run/vsftpd/empty
pam_service_name=vsftpd
rsa_cert_file=/etc/ssl/private/vsftpd.pem

I tried the command mentioned in the previous question to no avail.

sudo chmod a-w /home/user

Thanks, I appreciate all your help!