Apple has filed a counter-suit against Creative, resulting in Creative’s stock dropping 2.6%, reports Financial Times. “Apple alleged Creative infringed four patents for user-interface systems on the digital music players,” notes the story. “The suit was filed in response to a similar allegation against Apple by Creative, which is seeking damages and the suspension of sales of the Apple iPod in the US.” Analysts have said that they are not surprised by this countersuit, as the iPod is Apple’s fastest selling product. FT reports that Apple currently holds 77% of the US market, compared to Creative’s less than 10%.