Palm CEO Jon Rubinstein says he's optimistic about his company's future, but with its smartphone sales sagging and the mobile competition heating up, Rubinstein may be the only person who feels that way.

In its fiscal third quarter, Palm shipped 960,000 smartphones -- a 23 percent increase from the previous quarter -- but managed to sell only 408,000, which is 29 percent fewer than it moved in its second quarter. Its $150 million in quarterly revenues were well short of what analysts had anticipated.