QTP typing incorrect Text on PuTTY Window

[ShrikantBiradar3449]

Hi,

I am automating Backend flow and need to deal with 'PuTTY.exe'(a window application).

Find below link for reference:
http://en.wikipedia.org/wiki/PuTTY

I am using below code to type a string on PuTTY window:
Window("PuTTY").Type "Hi this is shrikant"

It is working fine most of the time but sometime it is typing wrong text(few small characters in capital or vice versa) as below:
"Hi this IS SHRIKANT"

While execution I am using below vbs to disable auto lock of my machine:

set wsc = CreateObject("WScript.Shell")
Do While True
WScript.Sleep (6000*10)
wsc.SendKeys ("{NUMLOCK}")
Loop

Attched the screenshots for reference.
   
Please help me to find why it is typing incorrectly.Has anyone faced this kind of issue on other applications while typing a text string on any object?

Thanks in advance for your help!
Shrikant