Using the /summon or /setblock command to spawn a dropper or a dispenser works but data tags cannot be used to specify the orientation.
To replicate:
Create a command block containing any of the following commands:
setblock ~2 ~ ~ minecraft:dropper 1 replace
summon FallingSand ~2 ~ ~ {Time:1,TileID:158,Data:1}
Both will spawn a dropper facing in the default direction of South, regardless of the value of Data (if placed against a wall the dropper will adjust to face away from the wall). Applying the data for repeaters, hoppers and comparators work fine.
Linked issues
is duplicated by 8
relates to 2
Comments 36

I can confirm this as well and would really like this to be fixed. Very frustrating.
Confirmed for 13w41a.
Bug still persists in 13w43a
Confirmed for 1.7.
Clone does not respect orientation with rails. There seems to be 2 separate issues here, one where the setblock command doesn't respect orientation of some blocks, and one where rail's default behavior is overriding the behavior of the setblock and clone commands.
Confirmed for 14w18b.
confirmed for 14w19a
Still present in 14w26b.

Fixed for all but the rails.
Confirmed