The difference is that by this: $Response->Status() you call a function, and by this you get the value of the "property" named Status from object or hash named $Response: $Response->{Status} . In the former case, you get a warning if no such sub exists: can't locate object method 'Status' .... It's intuitive to assume there should be setters/getters rather than accessing an object's internal properties like above. I would check my code for more of these. Btw the Apache::ASP and Changelog therein mentions some changes to what Status is set by default etc.

bw, bliako