At the beginning of the call, she said she was using version 20 of our software, and described a problem unique to v20. I answered her question and resolved that issue for her. Then she said she was having a problem with the macro list in a particular part of the software.
I tried to get her to tell me what the problem was by dexcribing what she was seeing on the screen, but the more she described what she was seeing, the more it became clear that she was not looking at the same peice of software I was. After a while, it seemed like she had never even used out software. Then I worked out that she was just doing a very bad job of describing an old version of our software. In v18, that part of the software was radically different. The third time I asked her, she admitted that she was in front of a computer using v18, and then promptly went to the computer running v20, where she saw that there was not actually a problem.
What the heck?