Patch 4.0.6 (8-Feb-2011): Now also causes Chains of Ice to root the target for 1/3 seconds.
Patch 3.2.0 (04-Aug-2009): Icy Clutch can no longer miss when Frost Fever hits, however, when Frost Fever is dispelled Icy Clutch will also be dispelled.
Patch 3.1.0 (14-Apr-2009): Now a 15/30/50% movement speed debuff (up from 30%).