I have a background worker control that is set to perform a task, and update a multiline text box on my main UI using a delegate procedure. this is all working perfectly, howeve
Try it this way:
'textbox.Text = text
textbox.AppendText(text)
The code you commented out wasn't running on the GUI thread, and as M Granja pointed out, AppendText will automatically scroll to the appended text in the box, so no need to call ScrollToCaret.
xxx.SetFocus ' xxx = the name of the textbox
SendKeys "^{END}" ' pop to last line