What it is
This error is a fairly basic one. 99 44/100% of the time, it occurrs in Global Village Teleport Gold modems. It usually appears when people attempt to send mail, but can also appear when any significant quantity of data is being transmitted (ie forms, FTP transfers and the like), and (rarely) as soon as Netscape loads.
Procedure
Try reconnecting now. If this didn't do the trick--