internetexplorer.application navigate error

Hi All
I have a simple vb script that opens IE window and navigates to a link:

Set oIE=createobject("internetexplorer.application")
Do While (oIE.Busy)
Wscript.Sleep 250
Loop
oIE.navigate "http://MyLink.htm"

Most of the time it works fine but sometimes I am getting "Invalid procedure call or argument" error on  oIE.navigate line
Is there anything I am doing wrong?

Thanks