Looks like people are losing their taste for smoothies. Jamba Juice, that perky chain of fruit juice and smoothie stores around the country, has been hit with hard times. Although revenue is up ten percent, same-store sales (that would be sales at stores that have been open for a while, and is an important indicator of a retail company's health) dropped 7.3 percent in the second quarter. And now, according to the East Bay Business Times, the Emeryville-based company's CEO and CFO have resigned to "pursue other opportunities." The company went public in 2006.