I have a similar issue...but with all my clubs.
I hit all of my clubs higher than anyone I have ever played with...but I don't have a distance issue, I jut hit my shots sky high for some reason.
For example, my tee balls start off a bit higher than most, but continually climb until they appear to hit a wall and fall, similar to what you describe. Its not a spin issue I don't think, as I am a sweeper, and my tee shots do get decent roll (10 yards maybe) they just don't have the penetrating flight like they should.
For me though, I'm hitting my drives about 270 consistently, so its not much of an issue. Sure I could be launching over 300 probably if I fixed it, but is there really a need? The other side of it too though, is that on my irons, while I'm only hitting my 7 iron 155y, it comes down from about 10 stories up, so it hits real soft and doesn't roll at all after hitting the green, so I know where I land it, is where its going to end up.