Well.... my dog has a potty mouth and said your dog must be a *****.
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(http://geekhack.org/attachment.php?attachmentid=6450&stc=1&d=1260933652)
OK I gave him a treat and he told me this.
Keyboards send make codes on the down stroke and break codes on the up stroke. Sometimes you can fool the controller with rapid key presses and a key gets "stuck". Usually a press or two of the key will unstick it.
Or drool caused it.
The "make codes" explanation makes sense (especially since my dog isn't a drooler lol). Thanks again Ripster! Oh and I'll be sure to pass along the message to my dog. Although, he might take those as "fightin' words" with him being a Doberman and all. :p