It seems that recharging Research in Motion's BlackBerry Bold can be a touchy issue.

At least in Japan.

Touchy as in hot as the smartphone's keyboard appears prone to overheating during the process.

Japan's top mobile carrier, NTT DoCoMo and RIM released a statement this morning that they are stopping sales just a week after launch to investigate the issue. Right now it's not the battery, RIM told InternetNews.com, and it's not an issue with any Bold products in other markets.

The Bold launched in the U.S. last year after a six- month delay.

AT&T, the exclusive U.S. carrier, told InternetNews.com that it had no comment on similiar complaints from customers, and referred to RIM's released statement.

According to Reuters the Japanese carrier had sold about 4,000 Bolds before sales were stopped, and received 30 consumer complaints on hot keyboards.

The Bold features a full QWERTY keyboard and more storage memory than previous BlackBerry models, with 1 gigabyte (GB) of memory built-in and another 16GB available with a SD memory card. In addition, the unit has a 624MHz mobile processor for faster document downloading.

An iSuppli report on costs of the 15 device components noted that the keyboard was the cheapest. The processor was the highest-priced device part at $34.34, the keypad assembly cost $1.85, the camera cost $9.90 and display cost $16.