A problem with keyboard and mouse

[Richard Charles Foster]

I am completely new to the world of Linux so please be patient with me!

I have just installed Ubuntu version 5.04 on an older computer (500MHz).
Everything works fine except for two problems.  Firstly, when I type using
the keyboard the computer thinks I have typed the same key three times (so I
get a string of letters rather than the word I wish to type).  Secondly,
when I click the left mouse button it thinks I have clicked it twice.  So,
for example, to get a drop down menu I have to click and hold in order to
see the menu.

Now this problem only occurs once Ubuntu has fully booted.  The username and
password screen are unaffected and I can happily input these without any
problem.  I have also tried using another keyboard that works fine on my
Windows computer and this does the same thing.  Further, although it
normally has this problem, on occasion I boot up Ubuntu and everything works
fine.  So I am pretty sure it is not a hardware problem.  I have also tried
fiddling with the repeat rate controls in the configuration but this does
not help.

Can anyone work out what is wrong?

Thank you so much for your help.

Yours faithfully,
Richard Foster.

Mr Richard Foster