Why would she do that?

Why would she do that. I get an unsolicited IM from one of my contacts. with out a hint, not a word of displeasure she drops the correspondence, then comes back with saying computer trouble. but then contacts another person a girl I suppose I'm a guy. it was mindless chit chat she said she was bored, I was searching the encyclopedia americana, all the while typing, to interest her. Why not just say i don't like you or I have to go an ugent appointment I forgot?