You are correct ..I have user control on page and at the end of user control following code was there for registering print library
after removing it its working fine
<object id="FetchPrnCls"
classid="CLSID:7D01D275-A46C-11D6-AA03-0050BA8D7BC3"
codebase="PrnProcess.CAB#version=1,0,0,7">
</object>
<object id="PrintingCls"
classid="CLSID:7D01D269-A46C-11D6-AA03-0050BA8D7BC3"
codebase="PrnProcess.CAB#version=1,0,0,7">
</object>
<object id="OthrFunctCls"
classid="CLSID:7D01D271-A46C-11D6-AA03-0050BA8D7BC3"
codebase="PrnProcess.CAB#version=1,0,0,7">
</object>