PC shipments unexpectedly went down rather than up in the first quarter.

Both Gartner and IDC promised they would be up as the economy improved. They were both fooled.

IDC promised a modest 1.5% gain. Instead its data said demand dropped 3.2% to 80.5 million units worldwide.

Gartner, on the other hand, which thought the market would be up 3%, found demand was down 1.1% to 84.3 million units.

That seems further apart than the two usually are.

Both blame the iPad, but that doesn't explain how come Mac sales were up 18.9% to 1.49 million boxes according to Gartner or 9.6% to 1.25 million according to IDC. Of course the MacBook Pro refresh at the end of February didn't hurt.

IDC VP Bob O'Donnell might be on to something when he says, "While it's tempting to blame the decline completely on the growth of media tablets, we believe other factors, including extended PC lifetimes and the lack of compelling new PC experiences, played equally significant roles."

His colleague Jay Chou added a bit more color, "‘Good-enough computing' has become a firm reality, exemplified first by Mini Notebooks and now Media Tablets. Macroeconomic forces can explain some of the ebb and flow of the PC business, but the real question PC vendors have to think hard about is how to enable a compelling user experience that can justify spending on added horsepower."

Gartner analyst Mikako Kitagawa found the same lack of sex appeal at fault. "Weak demand for consumer PCs was the biggest inhibitor of growth," she said. "Low prices for consumer PCs, which had long stimulated growth, no longer attracted buyers. Instead, consumers turned their attention to media tablets and other consumer electronics. With the launch of the iPad 2 in February, more consumers either switched to buying an alternative device, or simply held back from buying PCs. We're investigating whether this trend is likely to have a long-term effect on the PC market."

We can guess what she's gonna find when iPads aren't rationed anymore.

Other factors were also supposed to have played a role like the mess in Japan where PC sales were off 15.9% and events in the Middle East. IDC thinks their impact is likely to wear off by the second half. A cautious business mentality, the spike in fuel and commodity prices and the Sandy Bridge recall didn't help in a quarter usually soft for PCs.

IDC said US PC sales dropped more than 10%. Gartner puts the decline at 6.1%, down to 16.1 million units, finding laptops shipments down for the third consecutive quarter. Business sales were up, the public sector wasn't.

In the US it has Apple passing Acer to grab fourth place after HP, Dell and Toshiba, which was up 10.4% stateside. Gartner thinks Apple is still in fifth place after HP, Dell, Acer and Toshiba. Gartner gave HP 26.2% of the US but found it struggling in consumer PCs with tough price competition in the professional segment, especially the mid-market.

Worldwide IDC found everybody's growth off except Lenovo's (up 16.3%) and Toshiba's (up 3.8) with HP still first and Dell second. It has Acer down the worst, 15.8%, from the contraction in netbooks, which is obviously why it canned its CEO.

Gartner has Acer's global performance off 12.2% compared to HP (-3.4%), Dell (-2.2%), Lenovo (+16.6%) and Toshiba (+5.3%). It said Dell experienced a shipment decline year-over-year for the first time in six quarters, underperforming in the US, EMEA and Latin America, but achieving strong growth in Asia/Pacific.