Party Members Not Loading In Dawn/Promathia (And Possibly Other) Battlefields

Platform:
Windows 7 and Windows XP (happened on two computers)

ISP:
U-Verse AT&T

Type of Internet Connection:
DSL

Internet Connection Speed:
4.89Mbps

Date & Time:
18:30 and 19:00 PST (rough estimates)

Frequency:
It happened both times my group entered the battlefield. (Other members were experiencing the issue it as well)

Character Name:
Leocon

Race:
Elvaan Male

World:
Siren

Main Job:
Paladin 99

Support Job:
Warrior 49

Area and Coordinates:
Empyreal Paradox (inside the arena)

Party or Solo:
Party; 4 Members plus 2 Trusts.

NPC Name:
None

Monster Name:
Promathia

Steps:
My group entered the iLv Dawn battlefield and upon entering some members failed to load properly. When running far enough away for them to exit draw distance and then running back into draw range they would reappear however. I was unable to target them until this was done however; not even the macro command <stpt> would work on them, although AoE spells like Protectra did land on them.