Senior executives of notebook and Tablet PC maker Acer revealed this week that Microsoft is charging the company far too much for Windows XP Tablet PC Edition, the OS that powers Tablet PC devices. The result, according to Acer President Wang Chen-tang, is higher-than-necessary Tablet PC prices and lower-than-expected sales. According to the officials, Acer originally believed that Tablet PC sales would account for 20 percent of all its notebook sales, but the company has fallen far short of that goal, with Tablet PCs accounting for just 5 percent of sales a year after the devices first launched. Acer isn't alone. Poor Tablet PC sales have caused many companies, including HP and Toshiba, to delay the introductions of their second-generation Tablet PCs, an ironic event in some ways given that these machines address virtually all the shortcomings of the first-generation models, shortcomings that no doubt played a part in the units' poor sales as well. In any event, the price premium for Tablet PCs over typical notebooks is the number-one factor killing sales, Acer says, and almost all of that extra cash is going to Microsoft. "We have tried to negotiate the fee with Microsoft several times in vain," Wang said. "It's very regrettable. I hope the people in Redmond can hear us."