It would be best if you contact us the "help" button in your control panel.
A good place to start is to look at the server log file and see if anything in there sticks out. If you don't see anything you can try disabling Bukkit on your server to see if it runs fine, if so then you know that your plugins is plugin related and you can start checking each one for an issue.
<@TimeX-NFo> Hey, we used to have to carry our packets to the servers.
<@TimeX-NFo> And it was upstream, both ways.
<@TimeX-NFo|away> You're asking the old dude for help?????