Why might my keyboard produce extra characters with some keys. e.g. tab does the tab and then produces '#'. It doesn't happen as soon as my machine is switched on but once it starts behaving like this it continues almost constantly. Other affected keys seem to be 't', 'y' and various number pad keys.
ensure that your keyboard is tuned in the the UK English dictionary and that your number lock on the key pad is off - as for the t and y keys im not sure
I don't suppose you've spilled anything on it? I regularly spill water on mine and even justa few drops seems to get it behaving erratically, just like the way you describe.