Keyboard and typing problems

Hi,

I have a Studio 1535 (purchased March 2009), which developed a keyboard problem yesterday. Certain keys trigger multiple or incorrect characters, such as:

• Typing "i" produces "pi"; holding "i" down produces "piiiiiiiiiiiiiiiiiii"
• Typing "p" produces "pi"; holding "p" down produces "piiiiiiiiiiiiiiiiiiiii"
• Typing typing "[" or "]" produce "[]"
• Typing "k" or ";" produces ";k"
• Typing single quote (') also triggers the ALT key
• Typing "," produces "\,"
• Typing "8"  or "0" produces "08"

I confirmed these using the keyboard test in the Dell Support Center software, and also connected an external USB keyboard which worked fine. To help troubleshoot, I sprayed a few brief blasts of "air in a can" through the keys, which did not help. I have also not installed any new software or made any system changes in several months. At the moment, I suspect it might be a keyboard hardware failure.

Are there other tests to verify that this requires a replacement keyboard? If this is a hardware problem, can I purchase a replacement keyboard from Dell?

Thanks for whatever help you can offer,

Mike