Rock-
How long do you drop to your second fly on a nymph rig?
I could see where a long drop to your second fly could cause some tangles. We've always fished with about 8-10" (don't measure..just pull tippet out and "guesstimate" lol) drop from our first nymph. I've never had problems with tangles. I will shoot some line occasionally with a nymph rig if the situation calls for it...but most the time I am roll casting and dead sticking. You can get perfect "drag-free" drifts rolling and deading. IMO
-Rich