Ubuntu Networking :: Sharing Files On Windows Workgroup - Error 255

I've just recently got my samba confg working with a workgroup. I can view/access/modify windows machines on workgroup just fine. What I can't do is access shares created on ubuntu desktop. My ubuntu machine appears on Windows Workgroup, but denies to Windows users. When I try to create a share using Folder Sharing, I get this returned to me:
'net usershare' returned error 255: net usershare add: cannot convert name "Everyone" to a SID. Invalid parameter.

Here's by samba config file.
[global]
workgroup = JANSSEN HOME
server string = UServer
encrypt passwords = No
map to guest = Bad User
obey pam restrictions = Yes
pam password change = Yes
passwd program = /usr/bin/passwd %u
passwd chat = *Entersnews*spassword:* %n
*Retypesnews*spassword:* %n
*passwordsupdatedssuccessfully* .
username map = /etc/samba/smbusers
unix password sync = Yes
syslog = 0
log file = /var/log/samba/log.%m
max log size = 1000
dns proxy = No
usershare allow guests = Yes
panic action = /usr/share/samba/panic-action %d

[printers]
comment = All Printers
path = /var/spool/samba
create mask = 0700
printable = Yes
browseable = No