The Supreme Court on Monday heard arguments from Microsoft Corp. asking it to overturn a $290 million patent infringement judgment against the world's largest software maker, a ruling that could have a profound effect on how corporations protect and profit from their future inventions.

An eight-justice court on Monday heard arguments from the Redmond, Washington-based Microsoft, which wants the multimillion dollar judgment against it erased because it claims a judge used the wrong standard.

Business groups are closely watching this case. The U.S. government made more than $64 billion off of international licensing and royalties from patents in 2009, with an expected growth rate of 15 percent a year. A ruling for Microsoft could make companies less likely to invest in new inventions, but a ruling for i4i, the company which brought the lawsuit against Microsoft, could make it harder for large corporations to fight off such challenges.

The Michigan Supreme Court says it will decide if judges can order a sewer system when septic tanks fail and spoil a lake.

The court says Thursday it will take an appeal in a case involving Worth Township along Lake Huron in Michigan's Thumb region. State regulators want the township to install a sewer system, but an appeals court said local government isn't responsible for the problems of private property owners.

Some septic systems are failing on a five-mile stretch between M-25 and Lake Huron in Sanilac County. Waste is being discharged into Lake Huron and its tributaries.

Worth Township says it can't build a sewer system without financial help from the state.

A lawsuit seeking class-action status accuses Harrah's New Orleans Casino of failing to protect its employees from dangerous levels of secondhand smoke.

The mother of a former Harrah's dealer who died of cancer last year filed the federal suit Wednesday against the casino's owner, Nevada-based Caesars Entertainment Corp. The suit claims Maceo Bevrotte Jr.'s cancer was "directly linked" to his prolonged exposure to secondhand smoke at the casino. The suit says Bevrotte worked at Harrah's for about 15 years.

The lawsuit seeks unspecified damages and asks a judge to certify the case as a class action for at least 1,000 current, former or future nonsmoking casino employees.

Caesar's spokesman Gary Thompson said the company doesn't comment on pending litigation.

A class action lawsuit is alleging that Fixodent denture cream may have caused serious problems.

ABC News reported that lawyers for two former denture cream users are accusing Proctor & Gamble of manufacturing a product that made their clients extremely ill.

Mark Jacoby, a 41-year-old construction worker who wore dentures for 20 years, told ABC News that he believes his debilitating neurological illness is due to the high zinc content in his Fixodent.

"I started getting tingling in my fingertips. And then it started happening in my toes," he told ABC News' 20/20 anchor Chris Cuomo, who is the Chief of the Law & Justice Unit. "I started getting weaker and, you know, I couldn't walk right, off balance and I'm at this point now."

He said his doctors searched for years for the cause of his debilitating neurological illness that robbed him of his independence.

The plan unveiled Monday includes tax increases for oil, gas and coal producers, investment managers and U.S.-based multinational corporations. The plan would allow Bush-era tax cuts to expire at the end of 2012 for individuals making more than $200,000 and married couples making more than $250,000. Wealthy taxpayers would have their itemized deductions limited, including deductions for mortgage interest, charitable contributions and state and local taxes.

"These policies were unfair and unaffordable when enacted and remain so today," Obama said in his budget message.

Obama's proposal would extend tax credits for college expenses and child care, as well as a more generous Earned Income Tax Credit for the working poor. The plan would enhance and make permanent a popular business tax credit for research and development, and would provide tax breaks for investing in advanced manufacturing and for making commercial buildings more energy efficient.

Many of the tax increases were in the president's previous budget proposals, offered when Obama could expect a more friendly reception from Congress. Lawmakers from both political parties, however, have been wary of limiting the ability of high earners to deduct charitable contributions out of concern it will hurt non-profit organizations.

A group of Senate Democrats has come out in favor of raising taxes on oil and gas companies, but Republicans, who generally oppose such tax increases, have the votes to block them in the Senate.