Pm me your Id and pass
1st. make sure you have java (6 or 7) version x64 installed.
2nd. run your server with this
CD /D "%BINDIR%"...
do you think u can post is server.properties?
Are you using his account?
ok, this a bit all crumbled up, so do you have permissions, and inside the Permissions folder ( Found in the same area where all the plugins are...
umm 1gb ram is way too little ram xD Get more ram and try reducing the max amount of players, turn off monsters/animals.
also get faster internet or rent a vps :d
its supposed to be like this :p
well, then i guess your gunna have to look at their ips and write down whos ip is who :D
and kickeveryone thats not on their own account
Use whitelist, in server.properties set whitelist= true
In the whitelist.txt, type in all the names of users allowed to join
Separate names with a comma.