When running Tests from QC, QTP stops identifying Internet explorer after first test completes



I'm running Test set/batch placed in QC. There are 5 test scripts lined up for execution in a sequence (one after another based on the condition).



  QTP opens IE browser in the first script and login to the application successfully,


  However in second script it doesn't identify the IE object.


Strange part  is if I close and Open the browser same scripts works fine. It seems QTP is getting closed/Reopened when QC executes the second Test.



1. In Remote agent setting, I have already Checked the option " Keep Quick Test open after test lab session ends"



Win 7 64 bit

QTP 11.0

IE 9.0.12


FYI, this issue is also observed on few Win XP machines.