Here are warlock's bugs I found:
1. Talents sometimes randomly switching on/off, for example some people say that 5/5 Imp. Corruption can't be casted while moving, but I've got 2.8 sec cast of Shadow Bolt without any points in Bane talent =) This is common mangos bug and happened on alt+f4, instance/bg entry, moving on other continent etc.
2. Voidwalker in aggressive mode and placed somewhere by "Stay" command often does not attack nearby enemies if they is unreachable by voidwalker melee attack.
3. Curse of Recklessness casted on feared target removes fear effect, but when I change this curse to something else, target ignoring fear and does not run away.
4. I can't start aiming of Rain of Fire while running, but aiming while running is not prohibited.
5. Instant cast of Corruption with talent Improved Corruption 5/5 often can be interrupted by moving shortly after cast button pressed - i.e. press cast button, then move in any direction. This issue may apply to instant cast of Shadow Bolt when Shadow Trance is active. It is because cast itself happens on server's time tick, but flag about spell interruption is set in network handler of moving data packets before time tick. Step by step:
-Warlock casts Corruption.
-Warlock moves in some direction.
-Server accepts packet of cast and puts information about cast in game logic.
-Server accepts packet of player move, finds in game logic pending Corruption cast and interrupts it.
-Server does sheduled timetick, but cast chancelled and nothing happens.
Moreover, instant casts can be cancelled by counterspell, but it's less annoying then interruption by moving in combat.
6. Can't use my imp's fire shield (by Sélenne)
7. Health Funnel drains too much health from warlock =(
to be continued...
PS: I can help devs in fixing bugs.