Importing Audio Problem.....

I have some 24bit audio samples that I use occasionally. FX, dialogue, strange noises, etc... I got them free from Computer Music magazine on a dvd. Up until now everything has been great. I copied them to my hard drive and have had no problems using these samples....until now. Before when I would import a wave file into SONAR, it would import as a mono file. Now it seems everytime I imoprt one of these files, it is imported as a stereo file. I know, no big deal. I could just convert it to mono. But my big question is: did I inadvertantly change a setting or hit a key that would enable this sort of thing? I swear, all the other times I have used these samples they have imported as mono. Weird! What gives? Also, I checked the box on the media browser pertaining to "import as a mono file".....it still imports stereo. Anyone have any ideas?