Before raising any bug, first try to understand and analyze 
it from requirement of view.

Do not come to conclusion that it is a software bug 
instantaneious if you are not getting the expected result 
in the application.  It can be a test case or test data bug 
meaning that the application is working fine but the 
expected result in the test case itself is wrong. It could 
be your misinterpreation of the requirement.

Hence, analyze it and come to conclusion that it is really 
a bug as it is not adhering to the requirement, RAISE it.