smg, How many bowls are you smoking a day? Is there a marked difference in the flavors you pick up with the first bowl of the day compared to the last?
Anyway, I have had this happen to me a couple times, even with heavy full bodied blends like Odyssey, Margate and Penzance. It wasn't as though I couldn't taste anything but it was more like all the nuances and complexities that I normally experience (the flavors that I was expecting to be there) were not coming through. Plain and simple, they were muted, and not at all registering in with the olfactory nerve a.k.a "the pleasure dome."
I thought my issues were sinus related but I am fairly certain in hindsight that it was good old fashioned sensory fatigue. This issue happens with wine tasting, beer sampling, or any other situation where your taste buds are spinning their wheels trying to keep up with what you are sending their way. Sometimes they just need a rest.
Give this a try. Put your pipe away for 3-4 days, even two and come back to it. The best smokes I usually have are the first ones after a bit of a pipe smoking lay off.
I know, I know, the worst advice to give out on a pipe smoking forum, afterall we're supposed to be encouraging each other to enjoy piping more, right?.
But seriously, give it a try. If you do, I'd be interested to read your findings.
Oh, and welcome aboard.