Probably you have confusion with the caps lock key and stroke "^i". Just hypothesis anyway. If this is not the case then at least not judge me.
So I made a code that I can test here, to explain what I mean.
Set Wsh = WScript.CreateObject("WScript.Shell")
Wsh.Run "notepad"
Wsh.AppActivate "Untitled - Notepad"
WScript.Sleep 100
Wsh.SendKeys "111..."
WScript.Sleep 100
Wsh.SendKeys "^a" ' (ctrl+a) Select All command
If by chance the caps lock key is off, above code will select all text, but stroke "^a" (or even "^(a)") will fail if caps lock is on. And contrariwise, if you use "^A" will fail with caps lock off.
There no way to get the state of caps lock (or other keys) in VBScript, but I found 2 work arounds, call them cheats if you like :)
A bit weird way to go, is to duplicate your SendKeys command.
Wsh.SendKeys "^a" : Wsh.SendKeys "^a"
To send stroke to caps lock in advance.
Wsh.SendKeys "{CAPSLOCK}" : Wsh.SendKeys "^a"