TORONTO – Rogers Communications says the economic downturn was a key factor that lead to a fourth quarter loss of $138 million.The company took a “non-cash impairment loss” totaling $294 million on its conventional television business “to adjust its carrying value to reflect a lower assessment of fair value amidst recent recessionary declines in advertising revenues,” said the press release announcing the company’s financial results.For the full year ending December 31, 2008, Rogers reported its operating revenues rose 12% to $11.3 billion, operating profits increased 32% to $4.1 billion and net income was up 57% to just over $1 billion....