Anyone had this calculator keyboard problem?

[webmasterpdx]

I have a problem with one key, the number 3.
When I press gently and gradually apply more force, I hear and feel the click, but 3 does not appear on the display. I have to press firmly. I can get 3 to appear again and again by pressing and releasing just enough (without clicking).

Every other key causes the number to appear when the click happens. It's caused me to often type something in and omit the number 3, as I felt the click and assumed that the 3 was input.

How long is the warrenty for this kind of thing supposed to last? I'm unsure as to when this problem started, but I only noticed it recently.