maybe it has something to do with that fact that ramen is more of a salty thing, whereas soda is LOADED with sugar. When you're eating the ramen the salty receptors on the tastebuds of your tongue are stimulated, that's why each mouthful tastes pretty much the same, so when you take a drink of a sweet soda your tastebuds aren't expecting it, so the receptors get a bit messed up and don't really know which taste to taste I guess. Also the fizziness could affect it too probably.
Ha, that sounds intelligent...but I just made it up right now! It sounds plausible though
