I have an american DJ fog hog (1000 watts) and I get the same strange smell, sometimes. Sometimes the smoke doesn't smell funny, but sometimes it does. At first I thought it had something to do with the time inbetween sprays (and thus the time the smoke fluid is in the heating element). But it seems that doesn't always apply . But I actually like the smell so no problems there
BUT there are special "perfumes" that you can mix in with you smoke fluid, you can make your smoke smell like strawberry, bananas, cocos, mint etc... Be carefull though, because when you mix in too much "perfume" it will start too stink again