My intrepid reporter, Mrs. B, often gives me the best Ms. S stories, mostly because they have to work together more often.
Mrs. B related to me that one day, while Ms. S was working the circ desk, she became engrossed in creating an online greeting card using the circulation computer. Ms. S spent quite a bit of time at it, getting the details just right, and was so thoroughly absorbed with her task that when a patron stepped up to the desk for help, Ms. S completely ignored him. Mrs. B, watching from afar, kept waiting for Ms. S to pause and ask the gentleman how she could help him, being as how he was standing a foot and a half away from her, clearly waiting to be assisted. She didn't. As for the patron, he didn't interrupt her, cough politely, or even say "Excuse me" or anything. He just stood there, waiting for Ms. S to wrap up what she was doing and ask if he needed help. Again, she didn't. She just kept right on plugging away at her greeting card.
Seeing that Ms. S was entranced, Mrs. B dashed behind the desk herself and asked the patron if she could help him. He explained that he was looking for a particular book and had been unable to find it on the shelf and wanted help to make sure we even owned it. Since this was all said aloud, in direct proximity to Ms. S, Mrs. B waited politely for Ms. S to catch wind of the conversation and realize she was hogging up the circulation computer that Mrs. B needed for this search. She didn't. Mrs. B finally had to tap her on the shoulder and tell her to get out of the way.
Now, I'm no stranger for using the circulation computer to do non-work related projects. However, I do not do them to the exclusion of my job. Neither Mrs. B nor I could think of any reason beyond sheer, pig-headed stupidity that Ms. S would so actively ignore a patron like this. I shudder to think of what goes on during her solo shifts on the weekends.