Game Limitations bug ?

Thread Title:Seems the game can't deal with numbers higher than 65535 when performing an overpowered magic burst

Platform:PC

Type of Internet Connection:
Specify the type of connection. (dial-up, DSL, CATV, Optic Fiber, Other)

Internet Connection Speed:
Specify the speed of internet connection. (Example: 768Kbit/s, 5Mbit/s)

Date & Time:7 May 201121h gmt+1

Frequency:Easily reproductible /always

Character Name:Mystouille

World:Gilgamesh (goodbye Gilgamesh)

Main Job:Blu/War 90/45

Area and Coordinates:Abyssea Altepa near conflux #4

Party or Solo:Alliance (6+4)

Monster Name:NM Dragua

Steps:

A] Spawn Dragua with bloodied dragon ear KI
B] Kiting near conflux #4
C]Used A Primeval Brew
D]Used 3 JA : Chain affinity , Burst Affinity , Convergence
E]Used 1 Ws : Chant du cygne (damage displayed almost 4k)
F] Used a Spell : Benthic Typhoon (damage displayed 3k) (and darkness skillchain 4k)
G] Used a spell : Everyone's Grudge (magic burst damage displayed 9k)
H]Dragua was defeated

When i brew'd (primeval brew used) dragua a strange fact occured
i was on a blue mage job and done the following combo (note: on a fresh popped one)

CA/BA/CO Chant du Cygne > Benthic Typhoon > Everyone's grudge
Damage displayed were approx 3k>4k>(skillchain 4k)>(burst 9k)

Since Dragua Have more than 80kHP i think the damage display on the magic burst are bugged since this poor beastie died when i launched EG

I've tried on the next one without CO and EG burst gave me numbers like 62K

Then when i've done it again with CO the same fact occured again

My question is : Are the displayed damage are reset to "0" when they are over 65535 damage or was it a bug only related to magic burst "status?"

sorry for my terrible english