keyboard and mouse flaky afer upgrade

this is very strange on both machines that i have just upgraded< keyboard and mouse input arevery strange (for instance, that was supposed to be a comma above). it is intermittent. caps lock comes on for no reason and does not show on the keyboard as caps lock. by hitting caps lock (and lighting the caps lock light) i get lower case -- but not for all characters. some keys do not register without going back and hitting them again. occasionally (until i turned off repeat), the space bar would go on spacing forever until i hit backspace. likewise, the mouse pointer sometimes works just fine but other times when i click it it selects everything from where i was to where it is, and there's no getting it to do otherwise. i would think it's just a bad keyboard, but this is happening on two different machines in two different locations. the only change i can think of is the upgrade to 3.5.13.2. have i misconfigured something? tia for any advice less draconian than total reinstall! -- dep The shortest distance between you and great fingerstyle guitar playing? The new instructional DVDs from Marjorie Thompson, available now at www.MarjorieThompson.com