Take the snap shots of the defect occurence and should 
check for the environment which we are using and in which 
the application was developed. If there is any difference 
in the environment we have to verify our base line 
document. If the environment we are using is correct we 
have to raise it as a critical defect. If we are using any 
other environment we have to ask the development team to 
provide us the correct environment and should start testing 
only after we get that environment.

karthik,
we need to check the test data also,which we entered 
correct or not.

Check weather the configuration of your system and the 
system which your developer are same. Some can not be 
reproduced when there is some difference in the system 
configuration also.

Try to explain him with the help of Snap Shot.

Thanks Karthik