I found the reason for my issue.
Thought of sharing it with you all in case you guys run into similar issue.
The problem was occuring because i was developing on QlikView version 11 SR2
but our test server was on QlikView 11 SR1
if i run my dashboard on Qlikview version 11 SR2 , the problem does not occur.
The issue was occuring due to version incompatibility.