Sorry for my English.
Issues appears totally unpredictable way - on different version and different environment (single- and multiplayer).

Issues on vanilla 1.8.8 singleplayer:
- two consecutive repeaters CAN'T correct transmit through self impulse duration 4 ticks!
- two torchs activate at different time from one 4 ticks impulse. And different result from different direction of impulse.
- One torch is blocking other WITHOUT physical contact!

I'm made video with issues on different environment:

https://www.youtube.com/watch?v=ZnrAc4rYbs0

Timecode (all impulses have 4 ticks):

(version 1.8.8, server spigot, issues identical on vanilla)
1:40: outputs active at different time from one 4 ticks impulse. And different result from different direction of impulse.
3:20: most stupid bug. One torch is blocking other torch WITHOUT physical contact! (different direction - the same result).
6:05: two consecutive repeaters can transmit through self impulse.
6:30: strange work transmitter and receiver. A few strange stuff (6:50, 8:02)

(version 1.8.8, singleplayer)
9:31: two consecutive repeaters CAN'T transmit through self impulse! (compare 6:05)
10:25 - 11:25: all bugs are the same, but 1:45 - different direction - different result (compare 3:20).

(version 1.5.2, signleplayer)
12:45: most stupid bug. One torch is blocking other WITHOUT physical contact!

(version 1.8.8, server bukkit)
13:34: most stupid bug. One torch is blocking other WITHOUT physical contact!
13:45: two consecutive repeaters CAN'T transmit through self impulse! (compare 6:05 and 9:31)

Sorry for my English, and i have a big request:
Treat this issue seriously, because this bugs make impossible to make Redstone devices, please