The BlackBerry Tour is suffering from a widespread defect that could seriously impact Research in Motion's bottom line, an analyst cautioned on Wednesday. The trackball on the smartphone is reported as clogging so quickly that it requires users to frequently clean it to keep it working; as most don't or aren't aware of it, a very high number of owners end up returning the Tour to the carrier. As many as 50 percent of all Sprint's Tours are being returned, while Verizon is "angry" enough that it's telling stores to expect a shift in support to Motorola's upcoming sma
