Re. the computer - I don't know for sure. All my connections are wired (some of my clients are wary of wireless connections). It's a nuisance in some ways, but there's less to go wrong. But software does corrupt on occasions, and I've found a really cold boot can help - I had to do it regularly with our previous cordless 'phone, and it's corrected a cache fault on my box a couple of times. Try switching the computer off, unplugging it, and holding the power switch in until the chips discharge (~ 10 sec.), and at the same time, taking the batteries out of your mouse (~ 1 min. this time). Then put everything back together and see how it goes.