What version of kix and kixforms are you using? I just set up an example scenario, and as the form hangs while waiting for mapping (as expected), it does not turn black. Below is the code I used to demonstrate, using kixforms 2.47.5.0.

 Code:
$System = CreateObject("Kixtart.System")
$Form1 = $System.Form()

$TextBox = $Form1.Controls.Add("TextBox")
$TextBox.Width = $Form1.Width
$TextBox.Height = $Form1.Height
$TextBox.Center()
$TextBox.Text = "Attempting to map drive X"

$Form1.Show()

MapDrives()

While $Form1.Visible
   $Nul = Execute($System.DoEvents)
Loop

Exit 0

Function MapDrives()
   Use X: "\\server\share"
   If @Error
      $TextBox.Text = "Failed to map drive X"
   Else
      $TextBox.Text = "Successfully mapped drive X"
   Endif
EndFunction