The Federal Court of Appeal has turned away an attempt by MediaTube Corp. — in its already-dismissed patent infringement case against BCE Inc. — to introduce potential new evidence in its appeal based on allegations its lawyers were engaged in a conflict of interest. The $350-million suit stretches back to 2013, when MediaTube and NorthVu Inc. jointly filed the case against Bell’s Fibe TV. The two alleged Bell’s IPTV service is using certain patents it owns without a license. The Federal Court tossed the case out in January last year, but the two filed an appeal — with NorthVu...