A group of IBM interns has spent the summer in San Jose’s foothills producing one of Silicon Valley’s top exports: Otpimism.

Twitter’s been having a rough couple of weeks. A researcher looking into the attacks that knocked Twitter offline last week discovered another, unrelated security problem.

Plus: Consumer prices are flat in July, and down year-over-year. Sales plunge at Abercrombie & Fitch and J.C. Penney. Most valley tech stocks fall, but Rambus shares soar after chip designer wins court ruling.

BEIJING — State-owned China Unicom said Friday it is talking with Apple about becoming an iPhone carrier but denied a report it has reached a deal and will buy 5 million handsets.

Boeing said Friday it has discovered another problem with its long-delayed 787 jetliner. The Chicago airplane maker found microscopic wrinkles in the skin of the 787’s fuselage and is installing a patch, said Lori Gunter, a Boeing spokeswoman.

Technology startups are having an easier time paying their bills, a sign that Silicon Valley’s economy is recovering, said Ken Wilcox, chief executive officer of SVB Financial Group.

Plus: Tech stocks, Dow, Nasdaq advance. Macy’s profit plunges in its latest quarter.

Applied Materials, the largest maker of semiconductor-production machinery, predicted fourth- quarter sales and profit that topped analysts’ estimates, signaling that the chip market may have bottomed out.

Sentencing has been postponed for a private investigator who helped Hewlett-Packard unearth private telephone records of board members and journalists.

SAN FRANCISCO — State education officials on Tuesday named the first 10 digital textbooks that meet California academic standards for high school math and science.