At least some of the decreases in shipments and revenues reflected the shift to the new webOS platform and the Pre, which Palm unveiled in January. It has scrapped its original PalmOS, though it still offers the Windows Mobile-based Treo smartphone line.

The touchscreen Pre received generally favorable reviews, especially for the way it implements multi-tasking in webOS, which enables several applications to run and interact at once. The phone, priced at $199 with rebates, is offered exclusively on Sprint.

It’s been estimated that Palm has sold about 150,000 of the new smartphones in its opening days, and analysts expect it to be selling a couple of hundred thousand per month by late Fall. But that compares to over one million of the new iPhone 3GS in its first weekend of availability. Palm faces aggressive smartphone competition from both Apple and Research in Motion, which has been seeking to expand the appeal of BlackBerry brand smartphones to a much larger consumer market.

That hasn’t stopped investors from bidding up the stock’s price: from $3.30 a share in early January to just over $14.00 today. In after hours trading today, the stock rose to $15.93, a jump of nearly 14%.