Cisco down $0.91 to $12.28, was the Nasdaq's No. 1 most active stock and may have been sharply lower on vague rumors, according to Briefing.com. Talk ranged from executive changes, to missing estimates when it reports results next week, to company officials refusing to sign off of the financial statements ahead of the crucial August 14th deadline. But analysts dismissed the rumors as empty chatter. "I would be extremely skeptical of anything like this flying around," said Raj Srikanth, a managing director at Deutsche Bank, who covers Cisco. "My sense is that the company will sign off on its numbers (in September), that it will meet estimates when it reports Tuesday, and that there are no big executive changes planned