Sterling,
By "problems" do you mean breakage; difficult lacing; or...?
I generally do 4x whenever I can on the drive side (3x;2x;1x on the non-drive side depending on my mood and what spokes I happen to have in stock - I like the way the pattern looks from right-to-left). It is a bit more tedious with small flange hubs and for road bikes I always have the pulling spokes exit from the outside of the flange. I have also found 15ga spokes w/spoke washers allows clearance between the spoke shaft and the head and gives a good seat into the flange body, but for best result you may have to slightly relieve the spoke holes (I use a drill press).
As Brandon mentioned, we went round 'n round on this a while back and will not come to a consensus I'm certain. However, there are differences in lacing patterns which can be felt in the riding (there are also differences in wheel building which can be felt in the riding as well!). The ideal would be for you to have two identical sets of wheels, one laced 4x & the other laced 3x, and see if you could tell the difference. Of course you have to use an assistant so you wouldn't know which ones where which (the Heisenberg principal applied to the "seat of the pants") and then if you couldn't tell a difference, go with what is easiest.
Hope this helps a bit......
Chuck Brooks Malta (another Nor'easter headed this way but only "slop" they say??) NY