Dunno. Read up on the Exception; it may be like cross-thread Exceptions that get thrown in debug mode but not in release mode.

I seem to have solved the issue by modifying my ClosePort sub to: Public Sub ClosePort() bAllowSndRcv = False If IsNothing(comPort) Then Exit Sub If comPort.IsOpen Then comPort.DiscardOutBuffer() RemoveHandler comPort.DataReceived, AddressOf comPort_DataReceived Threading.Thread.Sleep(200) comPort.Close() End If End Sub

Why do you want to press button twice? When UdpClient's constructor is executed with a port number, it binds to the port number provided. You can't rebind to that port again. Once the binding is done, call Connect() method to connect the socket. Navaneeth How to use google | Ask smart questions

Thanks. I understand now; You can reach to the form by Application.OpenForms[1]. This makes sense :)

This Google[^] turns up a bit. "Real programmers just throw a bunch of 1s and 0s at the computer to see what sticks" - Pete O'Hanlon

There is nothing built into to .Net to do this for you. You would need use a ManualResetEvent[^] that is accessible from both your invoked method and the method you would like to stop the former. Basically, you need to code your invoked method so it is stoppable. Take care, Tom ----------------------------------------------- Check out my blog at http://tjoe.wordpress.com

You haven't said why you don't want to use the overloaded constructor to instanciate the client and specify the port. The problem is that in order to listen for incoming data, you use the UdpClient.Receive method. This method blocks until data is received, and with UDP being a connectionless protocol, you can never guarantee when data will be recieved so your left with having to listen for any/all incoming data over a specific port. One way to achieve this is to run a UdpClient that listens for incoming data on a seperate thread which frees up the main thread to do it's normal work. A seperate UdpClient can then be instanciated in the main thread whenever you need to send data. I created a test project some time ago which you can download from here: http://www.box.net/public/frq1a08ozh It requires v2.0 of the .Net Framework but the source code should help point you in the right direction even if you using v1.1 Hope this helps Regards Wayne Phipps ____________ Time is the greatest teacher... unfortunately, it kills all of its students View my Blog