The ctrl key on both sides, first noticed when I started to have intermittent problems with shortcuts like ctrl+c, ctrl+x... doesn't always register and it doesn't help if I press the ctrl key harder because its purely luck to do anything that is associated with the ctrl key...Is this an indication that my hardware is dying?
I would second Simon12 on this. Although I would lean more towards the keyboard just being old and you might require a replacement. After all the Inspiron 6400 is a rather old model now, but a decent one at that.
Luckily enough the Inspiron 6400 is a great laptop for taking apart so it should be an easy task. Keyboards won't cost too much to replace either.