VB.NET socket, Threading and Database Problem

Question

OS: Winxp and Win2003 Visual Basic.NET 2003 MS-SQL Server 2000 hey all I am a newbie in vb.net but i have managed to build a simple chat server in vb.net using socket and a client connecting to it made in vb6. Some of the code in the server are based on the basic samples that i get from other authors. To give you an idea, the server uses sockets, multi-threading and a database connection to MS-SQL server 2000. the off line messages, contacts lists, current status of the rooms and conference rooms are stored in the database. The client app is already done and it already meets the requirements for connecting into the server, but my server has not been optimized to do its job since i am in the code,debug and learn level, i'm still trying to make it stable. But during my testing of the server it pops an error which i haven't solved for a few weeks now especially if the server is running for a longer period of time. I have searched to a number of sites but i wouldn't give me the exact solution to my problem. Problem: 1.)Once the server is running more than 24 hours and receives a bunch of chat messages from the client application it tends to slows down its response to the client although im testing it on a single user connection, what i did was only send a test flood of messages , then connect and disconnect a hundred times. 2.)After a hundred of test flood messages to the server and connect/disconnect session from the client, the server pops an exception error such as “operation not allowed on a non-connected sockets” but when i click ok button of the msgbox my client app sees that it is still connected to the server. The client could still send commands such as [user search but not on private and room chatting anymore] . 3.)When the server tries to save a data into the sql server it then gives me another error “the statement has been terminated”. 4.)the problem that i mostly see is during login, private and room chat, saving to database. Other strange behavior of the server is that it can still recieve a search user command and then reply for the result but when i try to do private or room chat, there it pops the error messages again and no reply to the client whatsoever. Questions 1.)Do you think vb.net can handle more than a hundred concurrent user online or more or maybe thousand? 2.)Do you think its a good choice to have the client built in vb6 and the chat server built in vb.net ? any ideas are welcome Guys please i really need your help with my problems ! Any comments, suggestion or modification of the code are welcome. I have provided the server code in my site, I've omitted some of the codes and classes, to get you into the direct point, i have posted additional information of my problem in my site and some other screen shot of the error. my site: http://www.geocities.com/jimmypearly/index.html Thanks [email protected] PS sorry for my poor english, i hope you understand.