The data values of all potions have changed on the shift from 1.3.2 to 1.4.2 - Speed potions (8 minutes) have gone from a value around 8K to 16K, Splash potions have gone from 16K to 32K - However the game is still brewing these potions under the 8K and 16K data value respectively, Although the potions with the 8K data value still work like they're supposed to they are now ending 3 minutes before they're designed and showing too (Effect and tooltip in inventory disappear at about (2:58), only potions taken directly from the creative menu are getting the new data value.