Its happened to me regularly. Its a quiet week, until Friday, when i'm swamped with calls about missing/wrong data, weird errors and 'urgent' problems.
I've often wondered why, and will use this blog to give my opinion.
As a software developer i am isolated from the need for the user or consultant to deliver on his day to day tasks. He consumes your software as a tool to accomplish his day job. It is easy for me to forget this. imagine for a moment your mobile phone hangs. its frustrating. now imagine you need to call your boss to tell him you are sick and cant work today, and then your phone hangs.
If you were able to now communicate with the maker of that mobile phone, you surely would not use nice words. His failing mobile phone, is putting you in a difficult position.
As a developer, the shoe is on the other foot. Your failing software is putting client facing consultants, or deadline approaching users, in a difficult spot.
The next time a consultant or user phones you on a Friday, he probably has a deadline which he is about to miss. he is probably frustrated , upset, and you need to understand and accept that as part of your job. remain professional, and HELP him/her solve the problem. understand what he needs, filter the real problem from the other items he may mention, be honest about what you can achieve, and take responsibility.