Keyboard command keys issue
Hi! I dont know what has happened, but every time I press fn / control / option or command key on my iMac's Wireless keyboard it "locks" itself to the mode and makes using the keyboard a nightmare. See attached pic where computer screen highlights what key is activated / locked.
Can someone please let me know how to turn off this functionality?
Many thanks in advance.
iMac (21.5-inch Late 2009), OS X Yosemite (10.10.2)