Why do I need to press and hold the keys on my keyboard for a second for it to work?

Why do I need to press and hold the keys on my keyboard for a second for
it to work?

This is one of the wackiest and weirdest problems I have ever encountered.
My keyboard was working absolutely fine till yesterday on Ubuntu 13.04.
However, when I boot to Ubuntu today, I suddenly find that all the keys
work, but I have to press and keep on holding them for about a second for
them to work.
This behavior is true for all the keys except for Num Lock, Caps Lock and
Scroll Lock keys, the indicator for them on my keyboard lights up as soon
as I press those keys.
I have not done any key-remappings and using the standard English (US)
keyboard layout. I have fiddled around with the settings for Keyboard in
System Settings, but to no avail.
I have Windows 7 as dual-boot and the keyboard works perfectly well on it.
Why am I facing such a behavior and how to normalize this?
PS - Using Logitech Classic Keyboard K100 (USB Model).