Updated from 3:46 p.m. EST

A Japanese mobile phone operator has stopped selling

Research In Motion


( RIMM) BlackBerry Bold because of overheating problems during battery charging, according to a report.

According to





halted sales of the high-end Bold after 30 customers reported the phone's keyboard area heating up. No users have reported being injured or their phones catching fire, the company said, according to



DoCoMo, which began offering the Bold to customers last week, has sold about 4,000 of the smartphones. According to

Information Week

, RIM is looking into the issue and said in a statement: "This issue appears to be specifically limited to the BlackBerry Bold devices sold in Japan since last week and sales of BlackBerry Bold devices in other countries are unaffected by this matter."

It's been something of a tough road for the Bold, one of RIM's many weapons in the phone war with


(AAPL) - Get Report



( PALM),


(NOK) - Get Report



( MOT),


and others. The phone, already delayed for launch in the U.S., was pulled from

Orange U.K. shelves

in October because of concerns about a 3G software-related problem.

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RIM shares closed up 1% to $39.94, and DoCoMo closed up 1% to $15.37.