[Mongrel]

(This happened on BrightBlade, a 0.5.2. server iirc)

This bug seems to allow the player to enforce a reset of his tick counter of the server. It might also be a genereal regen bug.
I'll give an example to make it clear:

Player:
Monk, Level 10 - 22 (seems to be level independant, but is more obvious the lower you are)
Equipment: 2x Sceptre of Destruction, Mempo of Likato, Jboots, Fungus Covered Scale Tunic (<- with this one being the most important)

Situation:
Engage battle with an enemy to lose Hitpoints.

Without doing anything at all, HPs will regenerate normally (normal Regen + Fungi Tunic).
However, whenever you hit a button (I used the various special attacks (Round Kick, Tiger Claw, Eagle Strike)), you get extra regen from the tunic (and possibly the normal regen as well).

This also happens when you're low on HPs, and running away from the mob. When you hit auto-run you get normal regen, but if you jump repeatedly while running you get the extra regen as well.