Some weird interaction with max HP, rounding error?

I am currently playing a Necromancer using Essence Drain. I notice that when i heal from my life flasks, i will be a few hit points short of my max life, but the game thinks I am still on max life. If I try to heal more with my life flask it won't drink as if I am at max hp. The only way to fully heal is then to hit a monster with my Essence drain or regenerate off of Lifesprig and the recovery effect triggers and tops off my life.

http://imgur.com/IqbGrZj Me at full health in The Submerged Passage

http://imgur.com/zHzFinc I took some damage, now I'm about to drink my Superior Sacred Life Flask, which should full heal me (1356 recovery, 1229 hp)

http://imgur.com/8BkS8g3 Now I've backed off from the pack and flasked up. You can see I still am a few hp points short of 1229 hp.

http://imgur.com/ky7HNAh Full shields but 5 hp short

http://imgur.com/ZzdThRc Casting ED at a zombie

http://imgur.com/8dOJGR3 Now full hp again

Same thing happens with or without Lifesprig equipped. Also I have Shavronne's Pace equip. While a few hp points short I will still gain the 30% ms bonus

*Edit: Tried a fresh instants in The Ledge without casting ED and took some life damage. Same results when i flask up, I will be a few points short of max.