Another thread problem... Cross-thread operation not valid (Resolved)

[Cade]

Does anyone know why I get this error?
Cross-thread operation not valid: Control 'TextBox1' accessed from a thread other than the thread it was created on.

It happens when I try to modify TextBox1's properties from a thread I created.

The thread is a private variable in a class which raises an event. The handler of the event raised is where I tried to modify TextBox1.

Code used to create thread
sckTick = New Thread(AddressOf CallbackTick)
sckTick.Start()

Code of event handled, in thread sckTick
Private Sub sckMainConnected() Handles sckMain.Connected
MsgBox("Connected", MsgBoxStyle.Information, "")
TextBox1.Enabled = True
End Sub

Any ideas what I'm doing wrong?